Article

In vitro starch digestibility, estimated glycemic index and antioxidant potential of taro (Colocasia esculenta L. Schott) corm

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Abstract

The purpose of this study was to determine some functional properties of taro (Colocasia esculenta L. Schott) corm, which can be a good alternative to the other dietary carbohydrate sources with its high starch content. The total phenolic and flavonoid content of taro corm was found as 205 ± 53 mg CAE/100 g and 61 ± 9 mg CAE/100 g, respectively. The antioxidant capacity of corm was determined as 452 ± 72 mM TEAC/100 g and 244 ± 73 mM TEAC/100 g, by the scavenging activity against ABTS and DPPH radicals, respectively. The free glucose content of corms was less than 1%, whereas the 60% of dry matter was composed of starch. According to the results, the taro corms’ starch was highly digestible and higher than the 50% of the starch was composed of rapidly digestible starch (RDS) fractions. The estimated glycemic index (eGI) of taro corm was 63.1 ± 2.5, indicating taro corm as a medium GI food and a good dietary carbohydrate alternative especially for diabetic people.

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... Therefore, tubers from Xanthosoma spp. could represent a potential functional food source for the patients suffering diabetes mellitus type II (Simsek & El, 2015). Regarding the malanga hypoglycemic activity, Eleazu et al. (2018) reported that aqueous extracts of raw and cooked malanga tubers showed in vitro α-amylase inhibitory activity, which could be linked to a reduction of postprandial levels of blood glucose. ...
... Considering the glucose as reference, food glycemic index has been classified in high (eGI > 70), medium (56 < eGI < 69), and low (eGI < 55), resulting in a good predictor for nutrition purposes (Foster-Powell et al., 2002). The starch characteristics have led to classify malanga as an intermediate glycemic index food (Simsek & El, 2015). Some factors, such as nutritional composition and processing, affect the change in blood glucose after eating a meal. ...
... According to Simsek and El (2015), the total phenolic and flavonoid contents of Colocasia spp. corm are 205 mg Catechin Acid Equivalent (CAE) 100 g À1 and 61 mg CAE 100 g À1 , respectively. ...
Chapter
Colocasia esculenta (L.) Schott and Xanthosoma sagittifolium (L.) Schott are the most popular tubers among the Araceas family. Their chemical composition related to their nutritional benefits could make these rhizomes a valid option for the nutritional and technological improvement of food products. This chapter provide a clarification about the correct nomenclature of both tubers giving an insight around the principle components and their health effects. The scientific literature review has primarily highlighted several in vitro and animal studies where the consumption (leaves and whole tuber) of Colocasia esculenta (L.) Schott and Xanthosoma sagittifolium (L.) Schott was related with certain antihyperglycemic, antihypertensive, hypoglycemic and prebiotic effects. Owing to their functional properties, different component from these rhizomes, specially starch, mucilage and powders are being used by the food industry. Their ability to behave as thickener and gelling agent has allowed their incorporation in baked food, food paste and beverages. This chapter suggests the development of more research around these rhizomes since they could potentially play, with other crops, an important role in the future sustainable strategies to feed the planet.
... [12]. na-Not applied ** [13,14]. ...
... In addition to antioxidants, taro phytochemicals display immunomodulatory, antioxidant, antitumoral, antimetastatic, antimutagenic, anti-hyperglycemic, and anti-hypercholesterolemic bioactivities. Moreover, taro is a potential alternative staple source, with a lower glycemic index than potato, and its consumption may decrease the incidence and prevalence of several diseases, including certain types of cancers [13,[15][16][17]. ...
... In addition, the presence of soluble and non-soluble dietary fibers can improve intestinal transit and possibly aid in colorectal cancer prevention. As a result of its gluten-free nature, taro flour has arisen as a promising substitute for wheat flour, boosting the Brazilian market for gluten-free derivatives [13,15,16,[27][28][29]. ...
Article
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Taro corms contain valuable bioactive molecules effective against cancer and cancer-related risk factors, such as carcinogens and biological agents, several pathophysiological conditions, including oxidative stress and inflammation, while controlling metabolic dysfunctions and boosting the immunological response. Such broad effects are achieved by the taro health-influencing compounds displaying antitumoral, antimutagenic, immunomodulatory, anti-inflammatory, antioxidant, anti-hyperglycemic, and anti-hyperlipidemic activities. Taro bioactivities are attributed to the combination of tarin, taro-4-I polysaccharide, taro polysaccharides 1 and 2 (TPS-1 and TPS-2), A-1/B-2 α-amylase inhibitors, monogalactosyldiacylglycerols (MGDGs), digalactosyldiacylglycerols (DGDGs), polyphenols, and nonphenolic antioxidants. Most of these compounds have been purified and successfully challenged in vitro and in vivo, proving their involvement in the aforementioned activities. Although these health-promoting effects have been recognized since ancient times, as well as other valuable features of taro for food profit, such as hypo-allergenicity, gluten-free, and carbohydrates with medium-glycemic index, taro crop remains underexploited. The popularization of taro intake should be considered a dietary intervention strategy to be applied to improve the overall health status of the organism and as supportive therapy to manage tumorigenesis.
... Cocoyam tubers contain naturally occurring compounds such as fiber, minerals, vitamins, phenolic compounds, and mucilage (Mwenye, Labuschagne, Herselman, & Benesi, 2011;Ndabikunze, Talwana, Mongi, Issa-Zacharia, Serem, Palapala, et al., 2011). Nutritional benefits, like highly digestible starch with intermediate glycemic index (Simsek & El, 2015) and the reduction of postprandial levels of blood glucose (Handajani, Harini, Yuliningsih, Afianatuzzahra, Hasanah, & Widiyani, 2018) have been reported. Despite the importance of these aroids as emergency crops, their high moisture content (>70%) is responsible for a rapid deterioration after harvest, with the consequent losses (Falade & Okafor, 2015). ...
... maturity at harvest, post-harvest management, and storage (Temesgen & Retta, 2015). As it was expected for a root crop, carbohydrates were the main constituent (Simsek & El, 2015;Temesgen & Retta, 2015). Both flours contained oxalates, with greater content in Colocasia spp. ...
... flour. Simsek and El (2015) reported an estimated glycemic index for boiled Colocasia spp. corm, by in vitro method, of 90.2 ± 3.6 and 63.1 ± 2.5 using white bread and glucose as references, respectively. ...
Article
The corms of cocoyams, specifically Colocasia esculenta (L.) Schott and Xanthosoma sagittifolium (L.) Schott are usually consumed as pastes. Nevertheless, the secondary corms, also named cormels, are not fully exploited. In this study, the chemical composition and functional properties of cormels from different botanical sources were evaluated, and the digestibility of the resulting pastes investigated. Colocasia spp. flour contained significantly higher protein (10.32% vs 9.65%), ash (5.65% vs 5.05%) and oxalates (0.32% vs 0.22%) content, and exhibited lower Amylab gel strength (773 g vs 1040 g) than Xanthosoma spp. flour. In the resulting pastes, micrographs revealed that starch gelatinization depended on cocoyam variety. Indeed, the very tight and closed microstructure of pastes containing Colocasia spp. flour led them to better stability during storage with lower syneresis. Lower protein digestibility was obtained in Colocasia spp. gels (67.56% vs 70.91%), but they showed faster (higher k) in vitro starch hydrolysis (0.0140 vs 0.0050) with lower estimated glycemic index (61.29 vs 65.84) than Xanthosoma spp. gels. The present findings offer ways to develop cocoyam based foods by using cormels, enhancing the applicability of cocoyams.
... In particular, there has been research conducted with regards to the digestibility of taro starch, identifying their glycemic index (GI) potential as well as potential phytochemical content, specifically phenolic and flavonoid content as well as antioxidant activity (Simsek, S., 2015). Taro corms were largely comprised of over 60% starch dry matter with a less than 1% free glucose matter. ...
... This is to be expected due to the overall nature of taro corms housing a significantly large proportion of starch content(Simsek, S., 2015). Of note however are both the Maui Lehua and Mana Ulu raw forms, which contained a large proportion of carbohydrates with 31.92% and 31.76% ...
Conference Paper
Taro (Colocasia esculenta), a starchy root crop, is widely consumed across Asia and the Pacific and exists as different colored varieties in Hawai‘i. Although nutritional information exists for taro, there is a lack of variety-specific compositional data. In this study, the nutrient content (proximate and mineral via ICP-OES), phytochemical content (carotenoid via HPLC-PDA, total phenolic via Folin-Ciocalteau assay, and total monomeric anthocyanin via pH differential method), and carotenoid bioaccessibility (digestibility and micellarization efficiency via three-stage simulated digestion) were compared for three non-commercial taro, Mana Ulu, Pi‘iali‘i, and immature Pi‘iali‘i (Keiki) with one commercial variety, Maui Lehua. Nutrient and phytochemical contents differed across each taro cultivar based on their raw and cooked forms (P< 0.05). Beta-carotene and lutein were the primary carotenoids across each cultivar, with Mana Ulu containing the highest carotenoid concentration. Beta-carotene exhibited digestive stability of 45.8% and a micellarization efficiency of 13.6% from Mana Ulu samples. Total phenolic content was 83.52, 76.04, 75.44, and 66.86 mg/100 g FW and total anthocyanin content of 10.02, 9.33, 7.32, and 6.93 mg/100g FW for Maui Lehua, Mana Ulu, Pi‘iali‘i Keiki, and Pi‘iali‘i, respectively. Cooked taro had significant polyphenol losses with total phenolic contents of 20.55, 17.73, 22.61, 25.93 mg/100g FW, as well as total anthocyanin contents of 3.19, 2.16, 2.12, and 2.88 mg/100g FW for Maui Lehua, Mana Ulu, Pi‘iali‘i Keiki, and Pi‘iali‘i, respectively. These findings indicate unique nutritional and phytochemical profiles amongst underutilized taro varieties, which could be better leveraged to improve nutrition and health outcomes. Overall, expanding variety-specific compositional data is critical to ensure reliable database information to assess the nutritional adequacy of diets.
... Taro (Colocasia esculenta), a member of the Araceae family, monocotyledons, is one of the most important root and tuber crops. It is consumed as a staple food and vegetable by more than 500 million people in regions of the Asian-Pacific, Africa, and America (Simsek & Nehir El, 2015). The underground corms and cormels of taro, the major edible parts, have a high nutritional value and are rich in a range of health-related compounds that protect against a variety of human diseases (Alcantara, Hurtada & Dizon, 2013;Pereira et al., 2018;Simsek & Nehir El, 2015). ...
... It is consumed as a staple food and vegetable by more than 500 million people in regions of the Asian-Pacific, Africa, and America (Simsek & Nehir El, 2015). The underground corms and cormels of taro, the major edible parts, have a high nutritional value and are rich in a range of health-related compounds that protect against a variety of human diseases (Alcantara, Hurtada & Dizon, 2013;Pereira et al., 2018;Simsek & Nehir El, 2015). ...
Article
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Taro ( Colocasia esculenta ) is an important root and tuber crop cultivated worldwide. There are two main types of taro that vary in morphology of corm and cormel, ‘dasheen’ and ‘eddoe’. The eddoe type ( Colocasia esculenta var. antiquorium ) is predominantly distributed throughout China. Characterizing the genetic diversity present in the germplasm bank of taro is fundamental to better manage, conserve and utilize the genetic resources of this species. In this study, the genetic diversity of 234 taro accessions from 16 provinces of China was assessed using 132,869 single nucleotide polymorphism (SNP) markers identified by specific length amplified fragment-sequencing (SLAF-seq). Population structure and principal component analysis permitted the accessions to be categorized into eight groups. The genetic diversity and population differentiation of the eight groups were evaluated using the characterized SNPs. Analysis of molecular variance showed that the variation among eight inferred groups was higher than that within groups, while a relatively small variance was found among the two morphological types and 16 collection regions. Further, a core germplasm set comprising 41 taro accessions that maintained the genetic diversity of the entire collection was developed based on the genotype. This research is expected to be valuable for genetic characterization, germplasm conservation, and breeding of taro.
... Uma vez que grande parte da resposta glicêmica é relativa ao potencial de hidrólise dos carboidratos por amilases digestivas, métodos in vitro que relacionem à cinética de hidrólise com a potencial liberação de glicose podem ser propostos, com grande possibilidade de alcançarem respostas bastante significativas e correlacionadas com o dado gerado in vivo. Na literatura inúmeros protocolos e propostas de estimativas podem ser encontrados, sendo necessário que se faça uma avaliação sobre suas reais aplicações para expressarem esta informação (Simsek & Nehir, 2015;Chung et al., 2008;Frei et al., 2003). ...
... Muitos trabalhos apresentam sob a denominação de "índice glicêmico in vitro" a expressão do grau de hidrólise de amido do alimento, apenas entendida como o computo do número de ligações glicosídicas rompidas, mas não trazem o computo da efetiva liberação de glicose como medida principal. Outros apresentam resultados que já incluem o computo de glicose liberada, mas a cinética de liberação não leva em consideração o tempo relativo para essa potencial resposta em situação pós-prandial (Simsek & Nehir, 2015;Chung et al., 2008;Frei et al., 2003). Research, Society and Development, v. 9, n. 10, e1809108572, 2020 (CC BY 4. (Silva et al., 2009;Nelson & Cox, 2014). ...
Article
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The Glycemic Index (GI) expresses the relative impact of the food's carbohydrate on the plasma glucose concentration, reflecting the fact that foods with a greater increase in the glycemic response after ingestion have a higher GI and vice versa. Knowledge of the GI of foods can guide the choice of the most appropriate foods for the composition of a healthy diet. However, studies to determine the glycemic index of foods are laborious and time consuming, since they are carried out with the participation of human volunteers. The interest in in vitro methods that can estimate this index has been growing. In this sense, the present study aimed to discuss the application of these in vitro methodologies in the estimation of the “glycemic index”, through a brief narrative review and the test of tests chosen to illustrate the reflection on the theme. The two methods tested here were able to respond to the starch sample and observing the quotes about the methodology allows raising questions such as: the use of in vitro methodologies presents itself as something promising, easy and quick to execute, but there is a need the adoption of a single in vitro methodology of choice, to be equated with in vivo, which allows comparison between generated data and the formation of a database of in vitro GI values.
... Multigrain beverages containing FOS (1.2 g/100 g) was analysed for GI. The glycaemic index of the multigrain beverage was found to be 45.07 which would categorize it as a low GI food (GI < 55) (Simsek & El, 2015). Use of whole grains rich in fibre along with additional sources of fibre like FOS may be responsible for the low GI of the beverage. ...
... Considering a serving size of the beverage to be 200 mL, it would contribute to a 10 g/100 g of the recommended intake of soluble fibre i. e., 25 g/day. The GI of the different multigrain beverage was found to be 45.07 which would categorize it as a low GI food (GI < 55) (Simsek & El, 2015). The prebiotic activity scores of the multigrain beverage was found to be 1.56. ...
Article
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Consumers are increasingly demanding healthier and natural foods made from whole grains. In view of this, a multigrain functional beverage was made using minor millets such as barnyard, foxtail and kodo millet. Millets are rich in dietary fibre, B vitamins and micronutrients like magnesium, iron and have low glycaemic index. Roasted millets were extracted with water and filtered to obtain the beverage. An appropriate ratio of all grain was obtained from D-optimal mixture design. Accordingly, grain amount was varied from 5 to 8 g, 8–12 g, 6–9 g for barnyard, foxtail and kodo millet respectively. The ratio was selected based on pH, phenolic content, antioxidant activity and sensory overall acceptability of resultant multigrain beverages. Beverage was treated with α-amylase enzyme, fructooligosaccharide, galactooligosaccharide, and maltitol to improve the sensorial properties. The final multigrain functional beverage was prepared from 7 g barnyard, 10 g foxtail and 8 g of kodo millet along with 1.2 g/100 g w/v of fructooligosaccharide, containing 5.72 g/100 g total dietary fibre, 47.69 mg ferulic acid equivalents (FAE)/100 mL total phenolic content with a prebiotic activity of 1.56 and 45.07 of glycaemic index (GI) which can be categorized as functional low GI beverage (GI < 55).
... The repeated process of autoclavingcooling may cause in the formation of the retrograded and crystallized amylose fraction . The amylose fraction bound to other amylose fractions via hydrogen bonds to form a double helix structure (Simsek and El, 2015). The structure of the double helix bound to the other double helix structures form crystals, therefore there was a recrystallization process of the amylose fraction, called RS3 formation process . ...
... These results supported the research of Deka and Sit (2016) which modified the starch using microwave treatment and HMT. Simsek and El (2015) reported starch gelatinization temperatures which were indicated by the increase interactions between amyloseamylose, amylose-amylopectin and amylopectinamylopectin, hydrogen bond formation between molecules and formation of larger crystallite structures. highest PV (240 BU) than the other treatments. ...
Article
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This study investigated the effects of annealing, autoclaving-cooling and heat moisture treatment on the microstructure and physicochemical characteristics of taro starch. The taro starch was treated by the annealing process (24 hrs, 50oC), the heat moisture treatment (HMT) (moisture 25%, 3 hrs, 110oC), and the autoclaving (15 mins, 121oC) - cooling (24 hrs, 4oC) with 1 and 2 cycles. The results show that the autoclaving-cooling 2 cycles (AC-2C) changed the microstructure of taro starch into a very compact and dense structure because of formed double helix bound that cannot be hydrolyzed by pancreatic enzymes so it can be converted became resistant starch as the prebiotic source. Pasting properties analysis showed that AC-2C improved shear stress resistance, heat resistance and low retrogradation modified taro starch (MTS). The AC-2C treatment increased water binding capacity (73.84%), solubility (44.58%), and swelling power (16.71%) of MTS. The water-binding capacity had a positive correlation with solubility and swelling power. The AC-2C treatment increased amylose content (27.40%) and decreased reducing sugar level (6.36%) of MTS, so it can encourage the formation of resistant starch to improve the prebiotic properties of taro starch. Modified taro starch AC-2C is the best compared to HMT and annealing based on microstructure and physicochemical characteristics.
... Despite its adaptation to tropical conditions, it has long been cultivated in some part of Europe and Mediterranean (Oscarsson et al., 2007). Presently in subtropical and tropical regions, it is being cultivated for its edible carbohydrate-rich tuber, which is the most eaten part of the plant and are formed underground (Simsek and Nehir El 2015). Like other tuber crops, the unprocessed corm has low amount of fat (0.2%) and protein (1.5%) (Amon et al., 2011). ...
... The fleshy tuber can be boiled, roasted or mashed into a meal and used as staple food or snack. Among the root tubers, cocoyam is widely prepared or processed into more consumable products such as chips, cereal bars, canned products, paste, beverage powders, and flour (FAO, 2008;Simsek and Nehir El 2015). Cocoyam is usually subjected to a suitable method of processing in order to improve its nutritional value. ...
Article
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Roasting and boiling are two of the domestic cooking methods which affect the phytochemical, nutritional and the overall health functionality of food. The present study evaluated the effect of different cooking methods on the polyphenol, antioxidant and inhibition of key enzymes linked to carbohydrate metabolism of Cocoyam. Polyphenol contents were determined using total phenolics and total flavonoid, antioxidant capacity using total antioxidant capacity, ascorbic acid, ferric reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric-induced lipid peroxidation inhibition while ability to inhibit α-amylase and α-glucosidase enzymes were assayed to determine it effect on carbohydrate metabolism. The results showed that total phenolic content, total flavonoid content, total antioxidant capacity, DPPH and reducing power were significantly (P < 0.05) increased in roasted sample while ascorbic acid content was significantly decreased in both treatments. Also the roasted sample exhibited highest inhibition of α-glucosidase, α-amylase and induced lipid peroxidation which is significantly (P < 0.05) different from raw and boiled samples. Pearson correlation test exhibited positive correlation among polyphenols content, antioxidant activities and enzymes inhibition. These results showed that roasting enhanced the polyphenol, antioxidant and inhibition of enzymes linked to diabetes mellitus and therefore, it could be used by food industries to enhance the polyphenolic and antioxidant contents of foods.
... The estimated glycemic index of the sorghum cultivars in the present study ranged from 70.33 to 79.25 (raw flours) and from 80.06 to 89.30 (cooked flours) using white bread as a reference (G1 ¼ 100). Both glucose (GI ¼ 100) and white bread (GI ¼ 70) can be used as reference foods for GI estimation (Foster-Powell et al., 2002;Simsek and El, 2015). Values obtained in this study were then adjusted to glucose by multiplying by 0.7 and accordingly, the eGI values were ranged from 49.23 to 55.48 and from 56.04 to 62.51 for raw and cooked flours, respectively. ...
... According to this classification, all sorghums in the present study could be classified as low (Tabat-NL) and medium (Wadakar and Tabat-C) glycemic index foods. Low, medium, and high glycemic index foods are classified in nutrition as the best, better, and good choices (Simsek and El, 2015) and accordingly the sorghums in the present study could be classified as the best and better food choices for diabetic people. In the respect of the control of glycaemia, both β-glucan and tannins contribute to lowering postprandial blood glucose levels. ...
Article
This study investigated the protein fractions, in vitro protein digestibility (IVPD), in vitro starch digestibility (IVSD), antinutritional factors, hydrolysis index (HI), and estimated glycemic index (eGI) of the raw and cooked flours of a new sorghum inbred line (high β-glucan type I non-tannin sorghum) compared to two popular Sudanese sorghum cultivars (low β-glucan type 1 non-tannin and type II tannin sorghums). Significant differences (P < 0.05) were observed in protein fractions, antinutritional factors, IVPD, IVSD, rapidly digestible starch (RDS), resistant starch (RS), HI, and eGI. Low β-glucan type II tannin sorghum showed the highest antinutritional factors and RS values, whereas high β-glucan type I non-tannin and low β-glucan type 1 non-tannin sorghum cultivars showed the least values (P < 0.05). Low β-glucan type 1 non-tannin sorghum had the highest IVPD, RDS, HI, and eGI values. Cooking significantly (P < 0.05) reduced the protein fractions, antinutritional factors, IVPD, and RS and increased the IVSD, RDS, HI, and eGI of sorghums. Based on low eGI of high β-glucan type I non-tannin sorghum cultivar, it can be considered a low glycemic index sorghum and could thus be the best choice for diabetic people.
... Tim pengabdian memberikan edukasi bahwa kimpul memiliki kandungan yang baik jika dikonsumsi serta dapat dikonversi menjadi produk lokal yang kekinian. Kimpul sendiri merupakan jenis umbi-umbian yang mudah dicerna tubuh, memiliki glukosa bebas di bawah 1%, memiliki aktivitas antioksidan sebesar 244 ± 73 mM TEAC/100 gr, dan baik digunakan untuk diet karbohidrat khususnya penderita diabetes karena memiliki indeks glikemik kategori medium yaitu sebesar 63.1 ± 2.5 (Simsek & El, 2015). Demikian halnya dengan rempah-rempah, tim pengabdian memberikan edukasi terkait manfaat yang dimiliki oleh rempah-rempah jika dikonsumsi secara tepat. ...
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Pokdarwis Bokoharjo merupakan kelompok sadar wisata Prabu Boko yang terletak di kawasan Prambanan, Sleman yang dikelilingi oleh Candi Boko dan Candi Banyunibo. Pokdarwis Prabu Boko aktif dalam kegiatan budaya dimana sebagian besar anggotanya bekerja sebagai tour guide serta bersama dengan Bumdes mengelola Candi Banyunibo. Hasil observasi menunjukkan mitra pernah memiliki UMKM yang memproduksi makanan keripik singkong namun karena pandemic Covid-19, kegiatan UMKM Pokdarwis tersebut terhenti, sehingga perlu dilakukan pemberdayaan kembali UMKM tersebut agar dapat membantu pemulihan pendapatan mitra dengan cara memproduksi makanan khas Bokoharjo. Langkah pendampingan yang dilakukan antara lain melakukan sosialisasi kepada mitra, menentukan produk unggulan yang akan diproduksi, memberikan pelatihan produksi produk inovatif pangan, pelatihan pengemasan serta pelatihan manajemen usaha dan pemasaran. Hasil program ini adalah terbentuknya kembali UMKM Pokdarwis, terciptanya makanan khas Bokoharjo yaitu getuk kimpul dan wedang dupak serta peningkatan pengetahuan mitra terhadap kimpul dan rempah-rempah maupun peningkatan keterampilan mitra dalam pengolahan produksi makanan yang baik maupun manajemen pengolahan usaha dan pemasaran.
... Praktek pengobatan tradisional telah menggunakan ekstrak daun talas untuk mengobati sengatan kalajengking, gigikan ular, dan keracunan makanan (Pawar et al., 2018). Umbinya juga digunakan dalam pengobatan konstipasi, alopecia, stomatitis, hemorrhoid dan kelelahan otot (Simsek and Nehir, 2015). Spesies talas C. antiquorium telah terbukti memiliki efek hepatoprotektif melawan kerusakan hati pada tikus yang diinduksi dengan CCl4 (Pawar et al., 2018). ...
Book
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Tahukah anda bahwa serat pangan bukan sekedar pencegah konstipasi ataupun pembersih saluran cerna semata? Serat ternyata memiliki efek fisiologis dalam spektrum yang sangat luas jika ditinjau dari sistem-sistem tubuh yang dapat dipengaruhinya, baik secara langsung maupun tidak langsung. Serat terbukti dapat mencegah perkembangan kanker, diabetes mellitus, obesitas, inflamasi, dan penyakit liver dan ginjal. Buku ini memaparkan hasil-hasil penelitian penulis terkait efek positif dari mengonsumsi serat pangan yang berasal dari tanaman umbi-umbian dan rimpang khususnya dalam mencegah perkembangan berbagai penyakit akibat diet berlemak tinggi. Bagian-bagian awal buku ini mengemukakan fakta perihal komposisi nutrisi dan senyawa bioaktif yang penting dalam ekstrak serat umbi dan rimpang. Pada bagian-bagian selanjutnya dideskripsikan secara jelas bukti-bukti empiris terkait potensi serat dalam mengintervensi jalur pensinyalan inflamasi, melindungi struktur dan fungsi saluran pencernaan, memodulasi diversitas dan komposisi komunitas mikrobiota saluran cerna serta mencegah perkembangan diabetes mellitus tipe 2, disregulasi lemak tubuh, dan efek serat terhadap nilai darah. Diskusi-diskusi dalam buku ini akan memberikan pemahaman kepada kita perihal aksi kerja serat dan turunannya (produk fermentasi serat di saluran cerna) dalam menyokong kesetimbangan fungsi tubuh yang stabil dan sehat. Membacanya akan menambah kesadaran kita untuk lebih banyak mengonsumsi serat.
... Taro is a significant source of carbohydrates which serves as the cheapest dietary energy source. Besides, it is an important source of fiber and digestible starch while being low in protein and fat (Simsek & Nehir, 2015). The moisture content of fresh taro corms is high (63.6%-72.4%), ...
Article
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This study aims to investigate the effects of slice thicknesses (2, 4, and 6 mm) and solar tunnel drying zones (zone I, zone II, and zone III) on the drying characteristics and thermal properties of taro slices, which were dried using solar tunnel drying (STD). To assess the drying characteristics of taro slices, the data from the drying kinetics were fitted with five different models. The adequacy of fit for the proposed models was evaluated using the reduced chi‐square (χ2), determination of coefficient (R2), mean relative percent error (P), and root means square error (RMSE). The results showed that, among the five drying models, the drying characteristics of taro are better expressed by the logarithmic model. The thinnest slices dried in zone III had the highest diffusivity (6.57 × 10–09 m2/s), lowest specific heat capacity (1.761 kJ/kg °C), and maximum thermal conductivity (0.268 W/m °C). It was also dried within a short period of time (5.5 h). The findings of this study provide evidence that STD zones and slice thickness have significant impact on the drying characteristics of dried taro slices. The effects of different solar tunnel drying zones and slice thickness on the drying characteristics of taro slices were investigated. The data obtained were fitted with five selected models. Among the five drying models, the drying characteristics of taro are better described by the logarithmic model. The highest value of diffusivity was recorded for the thinnest slices dried in zone III.
... Moreover, structural reorganization in the F60 variety, a consequence of steric hindrance, leads to a favorable conformation for resistance to enzymatic degradation, hindering the enzyme-substrate union. [36] The features exhibited by modified polymers can present inconveniences for their application in the confectionery industry due to their low SP level; however, this decrease in SP is favorable for its use in cosmetics, allowing greater stability in formulations because of the low absorption and water retention capacities of polymers, which allows the possibility of generating emulsions because of the zeta potential exhibited by these materials. [37] Additionally, easy degradation and improvements in thermal properties due to changes in the FA compositions of the Clearfield and Oryzica 1 MS varieties may present them as options for the production of bioplastics. ...
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The structural modification of starch improves its physicochemical and functional properties and develops new material. Our study aimed to modify rice starch obtained from three varieties using a solvent-free system involving gulupa seed oil and lipase B from Candida antarctica. We characterized six starches (native and modified), performed a digestibility test, and determined the particle sizes, zeta potentials, and calorimetric differences between the materials. All the starches presented a charged surface between −41.6 and −58.9 mV. The modified starches’ fatty acid profiles changed according to the rice variety used, namely, the proportions of C14, C16, and C18 acids. The modified Clearfield, F60, and Oryzica 1 starches showed fatty acid content increased 85%, 23%, and 73%, respectively. The features presented by the three varieties of starch open up the possibility of their industrial application; furthermore, the starch modification process presents economic and environmental advantages.
... Trolox was used as a standard, and the values were expressed as μM TE/g sample. For the Trolox equivalent antioxidant activity (TEAC), the spectrophotometric method reported by [14] was used. The ABTS solution (7.4 mM ABTS and 2.6 mM potassium persulfate), which was kept in the dark for 16 h, was diluted with 100% methanol until an absorbance value of 0.7 at 734 nm was reached. ...
Article
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In order to fulfill the objective of the comparative flavor profiling of hot and cold serving, different concentrations of hot (hot infusion) and cold (boiled and cold serving) roasted-steamed-germinated wheat beverages were prepared in order to explore the comparative profile of the amino acids, volatiles, taste, total flavonoid content (TFC), total phenolic content (TPC), and antioxidant capacities, including 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) and the Trolox equivalent antioxidant activity (TEAC). The instrumental analysis was performed using electronic sensors (an electric nose and an electric tongue), high-performance liquid chromatography, and spectrophotometry, and the statistical assessment was conducted using univariate (correlation pattern and heatmap) and multivariate (clustering and principal component analysis) analyses. The cold beverages at the highest concentration showed the highest values of TFC, TPC, DPPH, and TEAC, showing 32.31 ± 1.13 μg CE/100 mL, 202.37 ± 20.94 μg GAE/100 mL, 68.43 ± 3.41 μM TE/100 mL, and 126.66 ± 4.00 mM TE/100 mL, respectively. The correlation analysis revealed a remarkable correlation between the taste and the flavor compounds. The clustering analysis and the PCA clearly divided the key metabolites, which were attributed to the different tastes in the hot and cold beverages. This study clearly demonstrates the impact of different temperatures on the aroma metabolites, the taste, and the characteristics of wheat beverages.
... The most interesting part is that taro flour is gluten-free so can be used as a wheat replacement for the preparation of products suitable for celiac patients. The availability of soluble and insoluble fibers in taro also improves intestinal transit and reduces the risk of obesity and type II diabetes (Simsek and El 2015, Bahado-Singh et al. 2006, Simsek and El, 2012. ...
Chapter
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Tropical tuber crops are the third most significant food crops after cereals and pulses, and they are known as nature's energy stores. They contribute significantly to the global food security for more than two billion people in developing countries. The tropical tuber crops especially major tuber crops (Cassava, Sweet potato, Aroids, Yams) and minor tuber crops (Arrowroot, Yam bean, Chinese potato) are distinguished by their higher starch content and lower protein and fat content. These crops are high in dietary fibre, minerals including calcium, phosphorus, and potassium, as well as health-promoting bioactive phytochemicals including polyphenols, flavonoids, beta carotenes, and anthocyanin. Antioxidants are key tools for maintaining good health since free radicals play a critical part in the genesis of many illnesses. Coloured tuber crops, particularly beta-carotene-rich orange and anthocyanin-rich purple skinned sweet potatoes, are effective sources of antioxidants that can help to prevent cancer and hypertension. The major goal of this chapter is to focus on the nutritional, 308 Antioxidant Properties and Health Benefits of Horticultural Crops therapeutic, and possible anti-oxidant qualities of tropical tuber crops, as well as how they may be used to make gluten-free anti-oxidant-rich functional foods.
... esculenta (CA) is a plant of the family Tauraceae, called taro, eddoe, and is used for food and medicinal purposes [13]. CA extract is known to have antioxidant, antifungal, and antimicrobial effects [14,15]. The methanol extract of CA has exhibited antimicrobial effects against Porphyromonas gingivalis (P. ...
Article
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Background and Objective: There is increasing interest in preventing periodontitis using natural products. The purpose of this study was to investigate the effect of Colocasia antiquorum var. esculenta (CA) varnish on the oral microbiome and alveolar bone loss in a mouse periodontitis model. Materials and Methods: Antibacterial activity against Porphyromonas gingivalis (P. gingivalis) ATCC 53978 and cell cytotoxicity using CCK-8 on L929 cells were measured. Balb/c mice were assigned into five groups (negative control, positive control, CA in drinking water, varnish, and CA varnish). P. gingivalis was administered to the mice by oral gavage three times. After sacrifice, the oral microbiome and the levels of the inflammatory cytokine IL-1β and matrix metalloproteinase-9 were analyzed. Alveolar bone loss was measured using micro-computed tomography. Results: CA extract showed an antibacterial effect against P. gingivalis (p < 0.05) and showed no cytotoxicity at that concentration (p > 0.05). Although alpha diversity of the oral microbiome did not statistically differ between the groups (p > 0.05), the relative abundance of dominant bacteria tended to be different between the groups. The inflammatory cytokine IL-1β was reduced in the CA varnish group (p < 0.05), and no difference was observed in MMP-9 expression and alveolar bone loss (p > 0.05). Conclusions: CA varnish did not affect the overall microflora and exhibited an anti-inflammatory effect, suggesting that it is possibility a suitable candidate for improving periodontitis.
... Total starch content was measured according to a previously described reference with some modifications as follows (Simsek & Nehir El, 2015). Briefly, 100 mg of crushed beads and macrocapsules (passed through a 100-mesh sieve) were weighed into a tube, to which 4 mL of 80% ethanol was added, and incubated at 70 • C for 2 h with continuous stirring at 400 rpm. ...
Article
This study aimed to enhance the content of slowly digestible starch (SDS) and resistant starch (RS) by designing a type of novel shell-controllable calcium alginate/curdlan/corn [email protected] alginate (CA/CL/[email protected]) core–shell structured macrocapsule. These macrocapsules were obtained by coating calcium alginate/curdlan/corn starch beads with different concentrations of sodium alginate. The results of the swelling power indicated that as the concentration of sodium alginate in the shell increased from 0% to 0.5%, the swelling degree of the macrocapsules at 95 °C decreased from 5.64 ± 0.09 g/g to 4.30 ± 0.12 g/g. The in vitro digestion experiments indicated that the content of SDS and RS of the macrocapsules at a sodium alginate concentration of 0.5% reached 42.21 ± 1.04% and 28.82 ± 1.05%, respectively. These results suggest that the CA/CL/[email protected] core–shell structured macrocapsules have the potential to be used as functional foods for cardiovascular disease, diabetes, and obesity patients.
... TEAC of the roasted wheat extract was analyzed using the spectrophotometric method described by Simsek and El [22]. A mixture of 7.4 mM 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2.6 mM potassium persulfate was incubated in the dark at RT for 16 h. ...
Article
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The objective of this study was to investigate the possibility of using germinated wheat as a nutritionally improved novel cereal beverage. To enhance the health-related functionality of a germinated wheat beverage (GWB), the roasting time and temperature of germinated wheat were optimized using a central composite design and response surface methodology. The optimum roasting conditions were determined as roasting temperature of 180 °C and roasting time of 44.56 min, resulting in maximum total flavonoid content (0.74 mg CE/g), total phenolic content (1.95 mg GE/g), 2,2-diphnyl-1-picrylhydrazyl (DPPH) radical scavenging activity (5.10 μM TE/g), Trolox equivalent antioxidant capacity (9.45 mM TE/g), and γ-aminobutyric acid content (2.25 mg/g). The germinated wheat roasted with optimum conditions was prepared in two types of GWB (hot and cold), and the sensory characteristics were tested by consumers (n = 102). The cold GWB showed relatively high preferences compared to hot GWB in appearance, odor, taste, and overall acceptabilities. In the intensity results of the sensory properties of GWB, the cold GWB tended to have stronger browning, grain odor, and nutty taste than the hot GWB. Conclusively, this study showed that optimizing the roasting conditions of germinated wheat could achieve desirable sensory properties and consumer acceptance while improving the health-related functionality of GWB.
... While the fast digestible starch causes a rapid increase in the blood glucose, the slow digestible starch is completely digested in the small intestine at low speed. The RS fraction cannot be digested in the small intestine but becomes fermented in the large intestine (Simsek and El, 2004). In a study conducted in 1982, it was determined that some starches remained intact after enzymatic hydrolysis (Englyst et al., 1982). ...
Article
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In this study, resistant starch (RS)-enriched pudding production was performed in order to develop puddings with reduced glycemic index which could be consumed as functional milky dessert to cope with obesity and high blood sugar. Control sample without the resistant starch (RS) and three pudding samples with RS (1%, 2% and 3%) were prepared. Physical analyzes of the samples were performed, their sensory and rheological properties were examined and glycemic index analyzes were implemented in vitro conditions. With the addition of RS, the moisture content of the puddings decreased and there was an increase in L* value. The rheological properties of pudding samples were evaluated using a rheometer. Results showed that, the viscosities of the RS added samples were lower when compared to to the control sample. The glycemic index value decreased with the increase in the RS content of puddings. Sensory analysis test was performed to a group consisting of 10 panelists. 3% RS sample was determined to be more favorable. Analyzes showed that RS caused positive effects on pudding moisture, brightness, rheology and glycemic index. As a result of this study, it was found that the sample containing 3% RS had acceptable and favorable properties.
... The total starch content was used to indicate the starch loading capacity in the calcium alginate beads. The total starch content was determined according to the method described by Simsek & El (2015). Briefly, PS@CAB (100 mg) was mixed with 4 ml ethanol (80%) at 70 • C for 2 h with vortex mixing frequently. ...
Article
In this study, potato starch granules were encapsulated in calcium alginate beads ([email protected]) with the aim of slowing starch digestion. The microstructure, gelatinization property, and in vitro digestibility of [email protected] were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and in vitro simulated digestion experiment. The size of the fresh beads was about 2 mm and reduced to about 1 mm after drying. The encapsulation efficiency of starch was over 98%. Compared to the potato starch, the swelling power of PS20@CA2B decreased from 31.1 ± 0.4 g/g to 6.6 ± 0.4 g/g at 95 °C. DSC results showed that the peak gelatinization temperatures of potato starch encapsulated in the beads increased significantly (p < 0.05) with a maximum value a 69.87 °C, compared with potato starch (62.76 °C). The maximum value of enthalpy change was 11.47 J·g⁻¹, which was much higher than that of unencapsulated potato starch (7.56 J·g⁻¹). SEM images showed that potato starch granules were coated in beads by calcium alginate films. Moreover, slowly digestible starch and resistant starch contents in the beads increased to 27.5% and 18.3%, respectively, which were remarkably higher than those of potato starch without encapsulation (9.2%, 3.4%, respectively). This study proposes a new strategy for the slow digestion of starch by encapsulating starch granules in calcium alginate beads, which benefits people with type 2 diabetes or obesity.
... Despite its adaptation to tropical conditions, it has long been grown in parts of Europe and the Mediterranean (Oscarsson and Savage, 2007). It is currently cultivated in subtropical and tropical regions for its edible carbohydrate-rich tuber, which is the most eaten part of the plant and is formed underground (Simsek and El, 2015). Other plant tissues, such as leaves, flowers, and stems, are consumed depending on the variety and local cultural traditions, particularly in sauces, purees, stews, and soups. ...
Article
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S: Taro is primarily grown for the corm, which is a staple food for millions of people. It is an annual herbaceous plant that belongs to the oxalate-rich food group. Oxalate is a naturally occurring plant metabolite that is present in all plant-derived human diets. The accumulation of oxalate by crops and pasture plants has a negative impact on the nutritional quality of foods and feeds. Oxalate is a poisonous organic acid that has a significant impact on the eating quality. Acridity causes swelling of the mouth and throat. Oxalate-rich foods also reduce calcium bioavailability and increase the risk of kidney stones. About 75% of all kidney stones are made up primarily of calcium oxalate. Chronic kidney disease affects 10% of the global population, and over two million people currently receive dialysis or a kidney transplant. Oxalates in food can be reduced through physical processes, chemical treatments, and genetic improvements. Cooking root crops may improve digestibility, palatability, storage quality, and safety. Boiling significantly reduced the amount of anti-nutritional factors, resulting in higher food quality. Eating high-calcium foods and adding calcium to cooking are two other ways to reduce oxalates in the diet. Calcium salts are widely accepted and used as acidity regulators, firming agents, and stabilizers in processed foods. Taro corms' total soluble oxalate content also decreased during storage. Explicitly, genetic advancements can aid in the development of long-term solutions. The purpose of this paper was to investigate acridity, its health and economic consequences, and potential food-acridity-reduction mechanisms. This educates users about the dangers of oxalate and aids in the development of mitigation strategies.
... Regarding antioxidant activity, a better value was obtained with the FRAP technique; this is probably due to the fact that this foodstuff has an appreciable iron content (Mergedus et al., 2015) and therefore the affinity for ferric ions of the FRAP method. Simsek and El (2015) studied the total phenolic and flavonoid composition of taro corm, and determined that flavonoids were present in about a quarter of the total phenolic content. The main flavonoids found in taro corm were quercetin and antoncyanins (Awa & Eleazu, 2015;Terasawa et al., 2007). ...
Article
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This study evaluated the effect of the inclusion of rejected taro tuber flour (RTTF) on the productive performance in commercial hybrid pigs (Landrace × Duroc × Pietrain) during their post-weaning period. The experiment was established under a completely randomized design, comprising four treatments (0, 10, 20, and 30% inclusion of RTTF in the diet), using a total of 60 piglets with 15 repetitions each. The average daily feed intake (ADFI), average daily gain (ADG), feed conversion (FC), final body weight (BW), presence of diarrheas, mortality, and production cost, were determined. RTTF showed a high dry matter content, nitrogen-free extracts, gross energy, aspartic acid, glutamic acid, potassium, iron, polyphenols, and antioxidant activity. RTTF inclusion in the diet of pigs in the entire period (30-58 d) did not cause diarrhea or deaths and showed a quadratic effect on BW (p < 0.001) and ADFI (p < 0.001) and produced a linear effect on ADG (p = 0.006), FC (p = 0.003) and production cost (p < 0.001). In conclusion, the inclusion of RTTF in the diet of pigs after weaning (30-58 d) ranging between 0 and 30 % showed no effect on BW and ADFI, with a slight decrease in ADG and FC and a linear effect on production cost reduction.
... About 84-87% of the total phenolic compounds from the extract were comprised of flavones di-C-glycoside [187], [188]. Polyphenolic composition of taro corm was investigated by Simsek and Nehir (2015), and reported that one quarter of the total phenolic content was occupied by flavonoids [189]. In USDA 2013 database quercetin (28.7 mg kg -1 ) was listed as the main flavonoid content identified from taro corm [190]. ...
Thesis
Roots and Tuber crops plays an eminent, countless and complex part in feeding the world. These crops have the potential to eradicate poverty and improve food security. Starch is the principal component of roots and tuber crops. The significance of starch as a raw material in both food and non-food industries are increasing. In present study efficiency of ultrasound assisted extraction (UAE) to increase the yield of starch and polyphenols from lontan (Canna and Cassava) crops were analysed along with its influence on the physiochemical properties of extracted compounds. Extraction parameters (Temperature, time, solid: liquid ratio) were optimized through Box Behnken response surface design (BBD). Physiochemical and functional properties of starch and polyphenols were investigated through SEM, swelling and solubility index, oil and water absorption index, Total polyphenol yield, DPPH and ORAC assay. Starch yield obtained from canna and cassava at the optimum extraction conditions (Canna: temperature 40°C, time 10 min, solid: liquid ratio 1:30 g/ml; Cassava: temperature 40°C, time 10 min, solid: liquid ratio 1:25 g/ml) were 19.81% and 16.51% respectively. Obtained starch yield was found to be significantly higher than the yield attained through conventional extraction method without any significant or adverse changes in the physicochemical and functional properties. Total polyphenol yield from canna and cassava rhizome was 1061.72 mg GAE/&100g and 7644.46 mg GAE/&100g respectively. Total polyphenol yield obtained through UAE was found to be significantly higher than conventional method. Antioxidant activity of bioactive compounds analysed through DPPH and ORAC was found to be directly proportional to the attained polyphenol yield. From the obtained results it can be observed that UAE has the efficiency to increase the yield of starch and polyphenols without altering the properties of isolated compounds.
... It also possess appreciable amount of minerals, vitamins and essential amino acids like phenylalanine and leucine. Moreover, taro has small starch grains (Simsek and El, 2015) as compared to other food crops which can aid diabetic patients, the aged people and children with the allergy and intestinal disorders (Awa and Eleazu, 2015;Eleazu et al., 2014;Folasire et al., 2016). Taro is served as boiled or milled into flour then used for soups, biscuits, bread and making soup (Offor and Onyewuchi, 2013). ...
Preprint
The tuberous corm taro has significant contribution to the diets and economic benefit of resource poor people in West Africa. However, the crop remains orphan and it is primarily characterized by poor eating quality. In this regard there are no improved varieties and or even no well-established base population to improve taro for acceptable eating qualities explicitly in Nigeria. Totally, 188 taro accessions collected from gene bank were used to profile proximate, oxalate and minerals. The objective of the study was to classify the accessions in to relative homogeneous group and to identify the major quality traits contributing to overall diversity of the population. Analysis of variance showed highly significant differences among taro accessions for proximate, oxalate and mineral contents. The relationship between dry matter and total oxalate content was negative and highly significant. Hierarchical cluster analysis among taro accessions resulted in three clusters and accessions with high dry matter and low oxalate contents were grouped in third cluster. From Principal component analysis the first three
... The higher IVDDM in diets with CC is a result of its high starch content (60 %), of which 50 % corresponds to high and rapid degradation starch (Simsek & Nehir, 2015). As compared to the cornstarch, which has a higher starch content (70 %) (Deckardt et al., 2013) than the CC, only 20 % corresponds to the fraction of rapid dissapearance (Ferreira et al., 2018). ...
Article
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Publicado como ARTÍCULO en Agrociencia 52: 97-105. 2018. RESUMEN Los atributos nutricionales del cormo de malanga (Colocasia esculenta; CM) deshidratado permiten considerarlo como ingrediente alimentario para substituir a los granos conven-cionales en las dietas para rumiantes. El objetivo del presente estudio fue evaluar la sustitución del grano de maíz por CM deshidratado en la degradación in vitro y el desarrollo de cor-deros Pelibuey. La hipótesis fue que corderos alimentados con dietas con grano de maíz o CM tienen un desempeño produc-tivo similar. Las dietas con 0, 20 y 35 % de CM (base seca) y con porcentaje similar de proteína y energía se formularon para corderos en finalización. La cinética de degradación in vitro de la materia seca de las dietas experimentales se cuantificó en este estudio. Las dietas se asignaron aleatoriamente a 30 corderos Pelibuey (18.3 kg  1.21 kg) alimentados individualmente. El diseño experimental fue completamente aleatorio con tres tratamientos y 10 corderos cada uno. El peso y el consumo de alimento se registraron por 70 d, y después el rendimiento de la canal. Con el incremento de CM en la dieta la cinética de degradación in vitro de MS aumentó linealmente (p0.05). El porcentaje de degradación fue mayor en la dieta con 35 % CM en comparación con 0 y 20 %. Las variables productivas fueron similares en los corderos alimentados con dietas con 0, 20 y 35 % CM. El 30 % de CM puede substituir parcialmente los granos convencionales sin afectar las variables productivas de corderos Pelibuey en finalización. ABSTRACT The nutritional attributes of dehydrated cocoyam-corm (Colocasia esculenta; CC) allow it to be considered as a dietary ingredient to replace the conventional grains in ruminants' diets. The aim of this study was to evaluate the replacement of maize grain with dehydrated CC in the in vitro degradation and the growth performance of Pelibuey lambs, based on the hypothesis that lambs fed diets with maize grains or CC will have a comparable productive performance. Diets with 0, 20, and 35 % of CC (dry basis) and with a similar percentage of protein and energy were formulated for finishing lambs. The in vitro degradation kinetics of the dry matter in the experimental diets was quantified in this study. Diets were assigned randomly to 30 Pelibuey lambs (18.3 kg  1.21 kg) fed individually. The experimental design was completely randomized with three treatments, 10 lambs in each one. Body weight and feed intake were recorded during 70 d, and afterward, the carcass yield was also recorded. With the increase of CC in the diet, the in vitro degradation kinetics of DM increased linearly (p0.05). The percentage of degradation was higher in the diet with 35 % of CC as compared to the diet with 0 and 20 %. The productive variables were similar within the lambs fed diets with 0, 20, and 35 % of CC. The 30 % of CC can partially replace the conventional grains without any effect on the productive variables of finishing Pelibuey lambs.
... However, there are scanty reports on glycemic parameters of cassava and its popular products. Cooking and variety may both affect the glycemic properties of food products favorably by increasing their functionality as has been reported in some cases; taro corm (Simsek and El, 2015), rice flour (Thiranusornkij et al., 2019), and cowpea (Ratnaningsih et al., 2017). It is also still not clear whether in vitro methods of digestion for cassava may give a clearer understanding of the digestion process compared to the conventional in vivo method. ...
Article
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In Sub-Saharan Africa (SSA), the prevalence of diabetes mellitus (DM) is rapidly increasing even in populations with significant undernutrition. The role of energy dense staple crops such as cassava is under query and not yet well understood. In this study, varieties of cassava, made into popular SSA products (fufu and gari dough) were studied for their resistant starch (RS), rapidly digestible starch (RDS) and glycemic index (GI). While the glycemic properties of the varieties studied did not differ significantly, processing any variety into either fufu or gari distinctly impacted RS, RDS and predicted GI (pGI) differently. Specifically, fufu had highest range of RS (1.1-2.1 g/100g) while gari dough had highest RDS (1.1-1.4 g/100g) and pGI (54-67). The results from this probe imply that fufu, when consumed, will release glucose in a slower manner than gari, therefore may be better suited in the dietary prevention and management of DM.
... Gölevezin GI açısından değerlendirildiğinde özellikle Tip II diyabet hastaları ve zayıflamak isteyen bireyler için patatese göre daha uygun bir alternatif oluşturabileceği düşünülmektedir (Simsek & El, 2012). Gölevez kormu ise, orta GI besin olarak özellikle diyabetik insanlar için iyi bir diyet karbonhidrat alternatifi olarak gösterilmektedir (Simsek & El, 2015). ...
Conference Paper
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Amaç: Bu çalışmada gölevezin mutfak kültüründeki yeri, kullanıldığı yemekler, sağlık açısından yararları ve tüketiminin araştırılması amaçlanmıştır. Araştırma Yöntemi: Bu çalışmada nitel araştırma yöntemi ve betimleyici araştırma modeli kullanılmıştır.Araştırmanın verileri Anamur, Bozyazı, Antalya, Silifke ve Karaman’da yaşayan 10katılımcıdan 2018yılında elde edilmiştir. Araştırmada veri toplama aracı olarak yarı yapılandırılmış görüşme formu kullanılmıştır. Bulgular: Gölevez; Akdeniz bölgesinde, sahil kesimlerinde pata¬tes gibi yetiştirilen ve tüketilmekte olan bir bitkidir.Genellikle “gölevez” ismiyle bilinirken, bazı kesimlerde “kolakas” olarak da adlandırılmaktadır. Geleneksel mutfak kültürlerinde genellikle patates gibi haşlanarak, kızartılarak ya da sulu yemek şeklinde tüketilmektedir. Ayrıca katılımcılardan elde edilen bilgilere göre sarma, çorba, salatagibi farklı şekillerde de tüketilebildiği ortaya çıkmıştır. Sonuç ve Öneriler: Araştırmadan elde edilen verilere göre; Gölevez, yöre halkı tarafından üretimi devam ettirilmektedir. Gölevezin kendine has tadı, tüketim alışkanlıkları ve sağlığa yararlı olması sebebiyle üretimi yapıldığı düşünülmektedir. Gölevez, gastronomi turizmi, kültürü açısındanbirumut vaat eden bir bitki olarak düşülebilir.Gölevezin gastronomi turizm unsuru olarak değerlendirilmesi,üretiminde standarttın oluşturulması ve yöre halkına üretim ve pazarlama konusunda ilgili kurum ve kuruluşlar tarafından destek verilmesinin yararlı olacağı sonucuna varılmıştır.
... TEAC was performed as described by Simsek and El [33], with modifications. Briefly, an ABTS + stock solution was prepared with 7.4 mM ABTS and 2.6 mM potassium persulfate and mixed. ...
Article
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The purpose of this study was to develop a formulation of Sunsik with improved health benefits by adding germinated wheat (GW) and herbal plant extract (HPE) using a response surface methodology (RSM). The central composite experimental design (CCD) was used to evaluate the effects of Sunsik with added HPE (2–4%) and GW (10–20%) on total phenolic content (TPC), total flavonoid content (TFC), Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, gamma butyric acid (GABA) content, total color changes (△E), browning index (BI), water absorption index (WAI), and water solubility index (WSI). As a result of the CCD, the independent and dependent variables were fitted by the second-order polynomial equation, and the lack of fit for response surface models was not significant except in relation to WSI. The GABA content, TPC, and TEAC were more adequate for a linear model than for a quadratic model, and they might be affected by GW rather than HPE. Alternatively, the TFC, DPPH radical scavenging capacity, WAI, WSI, △E, and BI were fitted with quadratic models. The optimum formulation that could improve antioxidant and physicochemical properties was Sunsik with 3.5% and 20% added HPE and GW, respectively.
... The AC-2C modified taro starch showed a low degree (40-60) of polymerisation (DP) (Setiarto et al. 2018) to form a spherical microcapsule-like surface structure that resembles maltodextrin but with a larger microcapsule size (50-60 µm). Meanwhile native taro starch and HMT taro starch still have complex chemical structures with a high degree of polymerization (DP > 100) (Simsek & El 2015). This is likely the formation of microcapsule structures that tend to be irregular with a fairly large size of microcapsule (70-80 µm). ...
Article
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Taro starch was modified and used as an alternative encapsulant for the microencapsulation of Lactobacillus plantarum SU-LS 36 by spray drying. Modification of taro starch was conducted by heat moisture treatment (HMT) and 2 autoclaving-cooling cycles (AC-2C). Microencapsulation of L. plantarum SU-LS 36 by spray dryer was done at constant air inlet (125 o C) and outlet temperature (50 o C), feed flow rate (4 mL min-1), drying air flow rate (20 m 3 h-1) and air pressure (0.196 MPa). The modified taro starch AC-2C as an encapsulant material was able to produce round-shaped microcapsules and provided optimal protection during spray drying. The modified taro starch AC-2C is very promising to be used as an encapsulant for L. plantarum SU-LS36 since it showed better production yield (40.19%), high encapsulation efficiency (89.83%), protected the encapsulated bacteria from high temperature (70 o C), and showed the lowest viability decreasing during storage up to 6 weeks at room temperature.
... In particular, a number of studies have been conducted on in vitro starch digestibility, glycemic index, and resistant starch content of taro (Simsek & El, 2015), as well as the physicochemical, functional, anti-nutritional properties of taro flours (Aboubakar et al., 2008). ...
Article
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Tarhana is a traditional fermented food in Turkey, made of a mixture of cereal, yoghurt and baker's yeast as culture. In this study, wheat flour used in tarhana production replaced with taro (Colocasia esculenta (L.) Schott) flour (TF) and Jerusalem artichoke (Helianthus tuberosus L.) flour (JAF) at 5, 10, 15 and 20% levels. Some physical, chemical and sensory properties of tarhana samples were determined. Increasing TF or JAF ratio in tarhana resulted in a significant (p <0.05) increase in the ash and antioxidant activity. Mineral composition of the tarhana samples improved with TF/JAF usage especially at high addition ratios. Tarhana soup with 15‐20% TF or JAF gained higher consistency values compared to control tarhana. As a result of sensory analysis, high utilization ratio of TF and JAF decreased the taste‐odor and overall acceptability of the tarhana soup.
... The specie Colocasia esculenta is also called "yam" in Central South regions of Brazil, and its worldwide production is widespread mostly in Asia, Africa and Central America (tropical and subtropical regions). On these continents, it is the main source of human energy diet and is considered the staple food crops in some West Africa countries [1][2][3][4][5][6]. The taro, belonging to the Araceae family, is a starchy tuber and due to its high moisture content, suffers high postharvest losses. ...
Article
Purple taro tubers (Colocasia esculenta B. Tini) were used in extraction of starch by aqueous methodology. After isolation, the starch was characterised and subjected to physical modification by ultrasound technique, using different amplitudes (40, 50 and 60%). Starch characterisation was performed by thermal analysis, pasting properties, X-ray powder diffractometry and high-resolution scanning electron microscopy. The root presented high carbohydrate content and low protein and lipid content. The apparent amylose content obtained from native starch was 26.45%. From thermal analysis, three major mass loss events were observed for all samples, and due the modification, an increase in thermal stability was achieved. There was a decrease in transition temperatures during the gelatinisation process after sonicated samples. The degree of relative crystallinity was lower for modified starches. An increase in peak and final viscosities was observed for physically modified samples, accompanied by a decrease in pasting temperature. The size of the granules showed a slight decrease, and agglomerations were not observed in this studied amplitude range.
... P < 0.01). This was also in agreement with Simsek and El [23] that greater RDS content will lead to higher GI. The combination of acid methanol treatment with annealing (AMT-ANN) had significantly lower GI than native counterpart (P < 0.05). ...
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In recent years, there is growing interest in the nutritional implications of resistant starch in foods due to its functional properties and health benefits. This has resulted to the development of various modification techniques to induce the formation of resistant starch. This study aimed to elucidate the effect of different modifications on digestibility and thermal properties of sago starch. Sago starch was treated with hydrothermal treatment [heat moisture treatment (HMT) and annealing (ANN)] as well as combined modification of acid methanol treatment (AMT) and hydrothermal treatment (HMT and ANN), respectively. Combined modification (AMT-HMT and AMT-ANN) had more pronounced effect in increasing the resistant starch (RS) content and lowering the glycemic index (GI) of sago starch, especially in gelatinized form. Strong negative correlation was obtained between RS and GI in both raw and gelatinised starch. Combination of acid methanol treatment with annealing caused the highest increment in gelatinization temperatures of sago starch.
Article
Lipu taro (Colocasia esculenta (L.) Schott) is a popular tuber crop in China. This study investigated the physicochemical and digestive properties of Lipu taro flour (LTF) and starch (LTS). The results showed that LTF was composed of LTS (79.13%) and non‐starch substances including protein (7.71%), lipid (0.32%), dietary fiber (2.13%), ash (1.05%) and moisture (9.17%). LTF had higher content of enzyme resistant starch (ERS, 36.52%) and the anon‐starch substances of protein and dietary fiber can inhibit the activity of digestive enzymes, which led to that LTF had a lower digestive degree during the in vitro gastrointestinal digestion than that of LTS. Moreover, LTS shared similar nutritional compositions including total starch (about 88%) and moisture (about 11%) to the commercial starches including rice, corn and wheat starches (RS, CS and WS, respectively). However, LTS showed the smallest particle size (0.485‐7.211 μm) which conferred it the smallest DPn value (16725) compared with other high‐rapidly digestible starches (RDS) of RS and CS. The physical characteristics might have prevented the bonding of LTS to the digestive enzymes, leading to its lower digestive degree than that of RS and CS, and was comparable to the low‐RDS starch of WS. The results suggested that the consumption of LTF and LTS may not induce high glucose levels in human, suggesting Lipu taro is a healthy food.
Article
The aim of this study was to explore the volatile compound contents and antioxidant potential of wheat beverage at various stages of preparation. Samples of raw wheat (RW), germinated wheat (GW), steamed germinated wheat (SGW), and roasted-steamed germinated wheat (RSGW) were collected, their physicochemical and structural characteristics were analyzed, and their bioactive components, amino acids, volatile profiles, phenolics, and antioxidant potentials were determined by spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), High Performance Liquid Chromatography, and electronic nose. RSGW had the highest level of bioactive components (2.46 mg/g GABA, 0.72 mg CE/g total flavonoid content, 4.66 μM TE/g 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and 10.20 mM TE/g Trolox equivalent antioxidant capacity). Also, the highest level of phenolic acids, gallic, p-coumaric, ferulic, syringic, and caffeic acids, were detected in RSGW. The FT-IR spectra revealed similar band positions for all samples. A principal component analysis clearly discriminated each preparation stage and established that SGW and GW had the highest amino acid contents while RSGW had the greatest bioavailability and highest abundance of volatiles and phenolic compounds.
Article
A wide variety of Andean potatoes are grown in Ecuador, nevertheless there is no information on their physicochemical properties and digestibility. The objective of this work was to determine in vitro digestibility morphological, thermal and pasting properties of starches isolated from nine potato tubers marketed in Ecuador. Raw starches were resistant to enzymatic hydrolysis, but their digestibility increased significantly after gelatinization. Rapidly digestible starch (RDS) increased from 3.8 to 6.2 times, while the contents of both slowly digestible starch at 120 min (SDS120) and 240 min (SDS240) decreased from 17.9‐34%, and 10.2‐34% (raw starch), to 11.2‐20.1%, and 4.2‐16%, (gelatinized starches), respectively. Also, resistant starch (RS) content diminished from 33.7‐45.5% to 8.50‐14.8%. In addition, total starch (86%‐95%), average granular size (26.2‐47.23 μm) and pasting properties (Peak viscosity: 2,400‐3,240 cP; final viscosity: 1,236‐3,507 cP; breakdown: 2,236‐5,424 cP; setback: 510–3,477; and pasting temperature 60.6‐66.2°C) differed significantly (p<0.5). Amylose (21.1‐26.7%), and thermal properties (To: 57.1‐62.3°C; Tp: 58.2‐63.9°C; Tf: 59–64.9°C), except gelatinization enthalpy (67.7‐168.6 J/g), did not differ significantly (p<0.5). The starch consisted mainly of elliptical or round granules. This study provides important information for developing potato products, mainly those with reduced starch digestibility, using different potato varieties, accordingly. This article is protected by copyright. All rights reserved
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Taro is an annual herbaceous plant grown in tropical and subtropical regions. Its various parts including corms and leaves are rich in vitamins (C, thiamine, and riboflavin), minerals (calcium, phosphorus), starch, and various bioactive compounds. The phytochemicals and pharmacological potential of taro are effective in mitigating various health maladies including neurological disorders, internal hemorrhage, and cancer. Furthermore, taro possessed various functional properties having various commercial aspects. Taro starch has multifarious potential in the food industry. Taro is a novel ingredient being used as an emulsifier, stabilizer, and prebiotic for the development of various products. It is a rich source of mucilage used in the preparation of various products. The results of various studies endorsed that taro has promising prebiotic potential and is linked to the modulation of healthy gut microbiota. The nutritional, therapeutic, biological, pharmacological, and functional properties are in the limelight of the current review.
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Colocasia esculenta (taro) is traditionally reported to be rich in bioactive compounds with pharmacological properties, and it is a source of starch—a natural polymer with film-forming capacity. The present work aimed to use the crude dry extract from taro rhizome in high proportions to form polymeric films in association with PVA, for use as biomaterials to prepare wound dressing. The films prepared by solvent casting technique were analyzed to evaluate their physicochemical parameters, barrier, and mechanical properties, and in vitro biocompatibility, important attributes for the functionality and safety of films for wound dressing application. The starch contained in the taro extract showed good filmogenic properties after prior gelatinization in water and then blending with the PVA solution containing glycerol. Moreover, the films obtained were thin, smooth, transparent, shiny, and domain-free. SEM photomicrographs showed the existence of a continuous and homogeneous microstructure. Additionally, the blends were partially miscible and presented an altered crystalline structure. The thermal stability and mechanical resistance parameters were improved due to the presence of the taro extract. In addition, the parameters pertaining to the functionality of the films as wound dressings were improved, particularly in the films containing higher proportions of the extract, which is configured as an advantage, since the taro extract proved to be non-cytotoxic, biocompatible, with healing activity, and it comes from a renewable source. Crude extract from taro rhizome blended with PVA proved to be suitable for the intended purpose. Graphical abstract
Article
The impacts of different cooking methods (boiling, steaming, baking, microwaving, and frying) on chemical compositions, starch digestibility, and antioxidant activity of taro corms were investigated. Compared to raw taro, boiling and frying reduced crude protein and ash contents. Frying significantly increased crude fat and fibre contents but decreased carbohydrate content. All cooking methods reduced oxalate content, especially frying. Among the cooked products, the boiled taro had the highest rapidly digestible starch (RDS) but the lowest resistant starch (RS) contents. In contrast, the fried taro provided the lowest RDS but the highest RS contents. All cooking methods reduced the total phenolic content and antioxidant activity of taro. The boiled taro had the lowest antioxidant activity but the fired taro provided the highest. Frying was able to retain most of the health‐promoting compounds with the lowest oxalate content, however the high consumption of high‐fat fried taro may adversely affect human health.
Article
The effect of acylation with various short-chain fatty acids on starch fine structure, digestion and gut microbiota fermentation property was investigated. Nuclear magnetic resonance spectra of acylated starch convinced the existence of acyl protons. Consistently, Fourier transform infrared spectra showed a carbonyl CO vibration at 1730 cm⁻¹ due to the introduced acyl groups. X-ray diffraction (XRD) and small angle X-ray scattering (SAXS) studies revealed that the acylation destroyed the internal structure for providing a chance of rearrangement of starch molecules with the formation of a different fractal structures. More interestingly, compared with native starch, there were a higher Δρu and a lower Δρ for acylated starches, suggesting more ordered aggregation structures was formed inside the starch granules. Kinetics of in-vitro hydrolytic enzymatic model and Pearson correlation coefficients further confirmed the association between multi-scale structural order and digestion characters. Acyl groups introduced by acetylation, propionylation and butyrylation onto the starch molecules could be effectively released by the intestinal flora during the fermentation, specifically increasing their corresponding SCFAs production, respectively. The greater generation of the specific SCFA from the acylated starches following the microbiota fermentation may highlight their importance in the application in food and pharmaceutical industry.
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Sourdough bread has been beneficial due to its slow starch digestibility and low glycaemic responses. In the present work sourdough breads are prepared from millet flours (kodo, barnyard, little and foxtail). Low bulk density of millet flours can make them an excellent ingredient to be incorporated in sourdough bread. Chemical composition and technological properties of millet flours showed a higher dietary fibre in kodo and more protein in foxtail. Fermentation parameters like total acidity, pH and dough raising capacity were studied. The fuzzy logic sensory score of foxtail sourdough bread was found to be the highest (0.9895), therefore further study was carried for bread made of different foxtail concentrations (20%, 30%, 40%, 50%). It was observed that total dietary fibre in sourdough bread (foxtail- 20–50%; refined flour- 65-35%; chickpea flour (10%), tapioca flour (5%); guar gum and salt 1% each; starter culture (20%) and water 53–55%) was found to be in the range of 5.64 ± 0.23 to 9.27 ± 0.19. The glycaemic index of optimized bread was found to be in the range of 40.79–42.35 that falls under the group of Low GI food (GI < 55). The fuzzy logic sensory score of sourdough bread made from 20% foxtail flour containing 1% guar gum was found to have the best sensory score (0.7221).
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Taro (Colocasia esculenta L. Schott) is considered a dietary staple food crop for millions of people throughout tropical and subtropical regions. Depending on the cultivar, taro may contain oxalic acid deposited in plant tissues as calcium oxalate crystals, causing a very unpleasant burning sensation in the mouth. In the present study, oxalate content was quantified in four different parts of the taro corm, as well as variation in dry matter, Ca, and the oxalate content of corms harvested at different developmental stages, from 5 months after planting (MAP) to 13 MAP. The results revealed that the level of oxalates varies according to corm part and cultivar. The cultivars with the lowest and highest water-soluble and total oxalate content in the central part, which is critical for human nutrition, were VU268 (87 and 134 mg 100 g⁻¹ DW) and VU384 (182 and 230 mg 100 g⁻¹ DW, respectively). Water-soluble oxalates accumulate mainly in the central and lower parts, while insoluble oxalates are concentrated in the marginal part of the corm. Their content can be almost halved by removing a 1 cm thick marginal layer (peeling). The oxalate/Ca molar ratio ranged from 0.78 in the upper to 1.31 in the central part, suggesting that the bioavailability of Ca in corms could be low. The dry matter content and Ca, insoluble and total oxalate levels vary according to the harvest time. The lowest total oxalate content was determined at 8 MAP (the usual time for taro harvest), while water-soluble oxalates increased with growing period. The proper assessment of corm maturity before harvest is, therefore, a critical step in controlling corm quality. Taro breeding programs aimed at reducing corm acridity need to take into consideration these results when designing protocols for optimum nutritional quality improvement of new cultivars.
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Encyclopedia entry available at https://encyclopedia.pub/7369
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The nutritional compositions and their changes of eight different varieties of taros (colocasia esculenta (L.)Schott) during microwave vacuum drying were analyzed, and the quality parameters of dried products, including color, hardness, crispness, puffing rate, microstructure and sensory quality were studied. Results showed that the moisture content of fresh taro corm was in the range of 61.33-82.94%, and the content of moisture in Fenghua taro was the highest;the starch content of fresh taro corm was in the range of 15.87-30.25%, and the content of starch in Xiangsha taro was the highest .The highest sucrose content and the soluble protein content were observed in the Lipu taro
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The nutritional compositions and their changes of eight different varieties of taros (colocasia esculenta (L.)Schott) during microwave vacuum drying were analyzed, and the quality parameters of dried products, including color, hardness, crispness, puffing rate, microstructure and sensory quality were studied. Results showed that the moisture content of fresh taro corm was in the range of 61.33-82.94%, and the content of moisture in Fenghua taro was the highest;the starch content of fresh taro corm was in the range of 15.87-30.25%, and the content of starch in Xiangsha taro was the highest .The highest sucrose content and the soluble protein content were observed in the Lipu taro
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The nutritional compositions and their changes of eight different varieties of taros (colocasia esculenta (L.)Schott) during microwave vacuum drying were analyzed, and the quality parameters of dried products, including color, hardness, crispness, puffing rate, microstructure and sensory quality were studied. Results showed that the moisture content of fresh taro corm was in the range of 61.33-82.94%, and the content of moisture in Fenghua taro was the highest;the starch content of fresh taro corm was in the range of 15.87-30.25%, and the content of starch in Xiangsha taro was the highest .The highest sucrose content and the soluble protein content were observed in the Lipu taro
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Type 2 diabetes is increasingly prevalent in Asia, which can be attributed to a carbohydrate‐rich diet, consisting of foods in the form of grains, for example, rice, or a food product made from flours or isolated starch, for example, noodles. Carbohydrates become a health issue when they are digested and absorbed rapidly (high glycemic index), and more so when they are consumed in large quantities (high glycemic load). The principal strategies of glycemic control should thus aim to reduce the amount of carbohydrate available for digestion, reduce the rate of digestion of the food, reduce the rate of glucose absorption, and increase the rate of glucose removal from blood. From a food perspective, the composition and structure of the food can be modified to reduce the amount of carbohydrates or alter starch digestibility and glucose absorption rates via using different food ingredients and processing methods. From a human perspective, eating behavior and food choices surrounding a meal can also affect glycemic response. This review therefore identifies actionable strategies and opportunities across foods and meals that can be considered by food manufacturers or consumers. They are (a) using alternative ingredients, (b) adding functional ingredients, and (c) changing processing methods and parameters for foods, and optimizing (a) eating behavior, (b) preloading or co‐ingestion of other macronutrients, and (c) meal sequence and history. The effectiveness of a strategy would depend on consumer acceptance, compatibility of the strategy with an existing food product, and whether it is economically or technologically feasible. A combination of two or more strategies is recommended for greater effectiveness and flexibility.
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Taro and maize are agricultural products that have nutrients, especially fiber, so it is very good to be developed and its presence in the location of the activity is relatively abundant, so that further management is needed. The main objective of the community service activity is to provide guidance for the farmer group in the enau river village in downstreaming the locally owned raw materials in the form of taro and corn into processed products that have high sales value. The achievement is carried out with the theoretical and practical method of transferring appropriate technology accompanied by experts in their fields in the hope of ease of absorption and targeted plans. For convenience in implementing partners, it is divided into several small groups and is responsible for the products proclaimed. The results obtained in the form of 6 products consisting of flour, chips, taro cookies are preferred by all respondents, while cake is only 75%, while products made from corn which include nuggets and 100% corn donuts are preferred. The product is equipped with packaging that is labeled on each product
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Lehua and Bun-long (Chinese) variety taro corms and Hawaiian breadfruits were collected from major production sites in Hawaii. The macro- and micronutrients were analyzed and statistically compared. The Bun-long taro has significantly (p<0.05) higher protein, ash and macro-mineral contents when compared to Lehua taro and breadfruit. The dietary fiber content in both taro varieties is higher than USDA data for taro. Breadfruit has significantly lower fiber content but is higher in vitamin C than the two taro varieties. The monosaccharides, glucose and fructose, are significant in breadfruit but not in taro corms.
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The use of plant origin polyphenols as food ingredients, supplements or antioxidants is very promising as a future trend for human health and food stability. Free radical activity, responsible for human ageing and food deterioration could be delayed by the use of antioxidants present in fruit and vegetables. The aim of the present research was to evaluate and compare the antiradical activity of selected fruits and vegetable snacks as a new promising kind of functional foods. In the present study, seven commercial plant food snacks were analysed for the total polyphenol content and antioxidant activity evaluated according to the DPPH(•) and ABTS(•+) radical scavenging methods. The highest total polyphenol content was evaluated in chokeberry and blackcurrant chips extracts, apple chips contained significantly lower amount among all snacks. Chokeberry extract exhibited the highest antiradical activity when determined by the DPPH(•) and ABTS(•+) radical scavenging methods, while the apple and carrot chips extracts showed the lowest antiradical activity. DPPH(•) and ABTS(•+) gave comparable results and were highly correlated (r = 0.83, p < 0.05). Results obtained indicate that selection of plant matrices for snack production would be very important for consumer's health, as they are potential sources of dietary antioxidants.
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Taro (Colocasia esculenta L. Schott) is an important crop worldwide but is of particular significance in many Pacific Island countries where it forms part of the staple diet and serves as an export commodity. Escalating pest and disease problems are jeopardizing taro production with serious implications to food security and trade. Biotechnological approaches to addressing pest and disease problems, such as somatic embryogenesis and transgenesis, are potentially viable options. However, despite biotechnological advancements in higher profile agronomic crops, such progress in relation to Colocasia esculenta var. esculenta has been slow. This paper reviews taro biology, highlights the cultural and economic significance of taro in Pacific Island countries and discusses the progress made towards the molecular breeding of this important crop to date.
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To systematically tabulate published and unpublished sources of reliable glycemic index (GI) values. A literature search identified 205 articles published between 1981 and 2007. Unpublished data were also included where the data quality could be verified. The data were separated into two lists: the first representing more precise data derived from testing healthy subjects and the second primarily from individuals with impaired glucose metabolism. The tables, which are available in the online-only appendix, list the GI of over 2,480 individual food items. Dairy products, legumes, and fruits were found to have a low GI. Breads, breakfast cereals, and rice, including whole grain, were available in both high and low GI versions. The correlation coefficient for 20 staple foods tested in both healthy and diabetic subjects was r = 0.94 (P < 0.001). These tables improve the quality and quantity of GI data available for research and clinical practice.
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For nutritional purposes, starch in foods may be classified into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). RS may be further divided into three categories according to the reason for resistance to digestion. A method is reported for the measurement of total starch, RDS, SDS, RS and three RS fractions in starchy foods, using controlled enzymic hydrolysis with pancreatin and amyloglucosidase. The released glucose is measured by colorimetry, using a glucose oxidase kit. Values for RDS and SDS in foods obtained by the method reflect the rate of starch digestion in vivo. Values for RS are similar to the amounts of starch escaping digestion in the small intestine of ileostomates, and are a guide to the amounts of starch likely to enter the colon for fermentation. Results are given for a number of starchy foods.
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Reliable tables of glycemic index (GI) compiled from the scientific literature are instrumental in improving the quality of research examining the relation between GI, glycemic load, and health. The GI has proven to be a more useful nutritional concept than is the chemical classification of carbohydrate (as simple or complex, as sugars or starches, or as available or unavailable), permitting new insights into the relation between the physiologic effects of carbohydrate-rich foods and health. Several prospective observational studies have shown that the chronic consumption of a diet with a high glycemic load (GI x dietary carbohydrate content) is independently associated with an increased risk of developing type 2 diabetes, cardiovascular disease, and certain cancers. This revised table contains almost 3 times the number of foods listed in the original table (first published in this Journal in 1995) and contains nearly 1300 data entries derived from published and unpublished verified sources, representing > 750 different types of foods tested with the use of standard methods. The revised table also lists the glycemic load associated with the consumption of specified serving sizes of different foods.
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Integrating information about the glycaemic index (GI) of foods into the Caribbean diet is limited by the lack of data. Therefore, we determined the GI of eight staple foods eaten in the Caribbean and the effect on GI of crushing selected tubers. Groups of eight to ten healthy volunteers participated in three studies at two sites. GI was determined using a standard method with white bread and adjusted relative to glucose. The mean area under the glucose response curve elicited by white bread was similar for the different groups of subjects. In study 1, the GI of cassava (Manihot esculenta; 94 (sem 11)) was significantly higher than those of breadfruit (Artocarpus altilis; 60 (sem 9)), cooking 'green' banana (Musa spp.; 65 (sem 11)) and sadha roti (65 (sem 9)) (P=0.018). There was no significant difference in the GI of the foods in study 2: dasheen (Colocasia esculenta var. esculenta; 77 (sem 10)), eddoes (Colocasia esculenta var. antiquorum; 61 (sem 10)), Irish potato (Solanum tuberosum; 71 (sem 8)), tannia (Xanthosoma sagittifolium; 60 (sem 5)) and white yam (Dioscorea alata; 62 (sem 6)), and, in study 3, crushing did not significantly affect the GI of dasheen, tannia or Irish potato. However, when the results from studies 2 and 3 were pooled, the GI of dasheen (76 (sem 7)) was significantly greater than that of tannia (55 (sem 5); P=0.015) with potato being intermediate (69 (sem 6)). We conclude that dasheen and cassava are high-GI foods, whereas the other tubers studied and sadha roti are intermediate-GI foods. Given the regular usage of cassava and dasheen in Caribbean diets we speculate that these diets would tend to be high GI, although this could be reduced by foods such as sadha roti and white yam. The range of GI between the staples is sufficiently large that health benefits may be accrued by replacing high-GI staples with intermediate-GI staples in the Caribbean diet.
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Glycaemic index (GI) values for fourteen commonly eaten carbohydrate-rich foods processed by various methods were determined using ten healthy subjects. The foods studied were round leaf yellow yam (Dioscorea cayenensis), negro and lucea yams (Dioscorea rotundata), white and sweet yams (Dioscorea alata), sweet potato (Solanum tuberosum), Irish potato (Ipomoea batatas), coco yam (Xanthosoma spp.), dasheen (Colocasia esculenta), pumpkin (Cucurbita moschata), breadfruit (Artocarpus altilis), green banana (Musa sapientum), and green and ripe plantain (Musa paradisiaca). The foods were processed by boiling, frying, baking and roasting where applicable. Pure glucose was used as the standard with a GI value of 100. The results revealed marked differences in GI among the different foods studied ranging from 35 (se 3) to 94 (se 8). The area under the glucose response curve and GI value of some of the roasted and baked foods were significantly higher than foods boiled or fried (P<0.05). The results indicate that foods processed by roasting or baking may result in higher GI. Conversely, boiling of foods may contribute to a lower GI diet.
Article
Integrating information about the glycaemic index (GI) of foods into the Caribbean diet is limited by the lack of data. Therefore, we determined the GI of eight staple foods eaten in the Caribbean and the effect on GI of crushing selected tubers. Groups of eight to ten healthy volunteers participated in three studies at two sites. GI was determined using a standard method with white bread and adjusted relative to glucose. The mean area under the glucose response curve elicited by white bread was similar for the different groups of subjects. In study 1, the GI of cassava (Manihot esculenta; 94 (SEM 11)) was significantly higher than those of breadfruit (Artocarpus altilis; 60 (SEM 9)), cooking 'green' banana (Musa spp.; 65 (SEM 11)) and sadha roti (65 (SEM 9)) (P=0(.)018). There was no significant difference in the GI of the foods in study 2: dasheen (Colocasia esculenta var. esculenta; 77 (SEM 10)), eddoes (Colocasia esculenta var. antiquorum; 61 (SEM 10)), Irish potato (Solanum tuberosum; 71 (SEM 8)), tannia (Xanthosoma sagittifolium; 60 (SEM 5)) and white yam (Dioscorea alata; 62 (SEM 6)), and, in study 3, crushing did not significantly affect the GI of dasheen, tannia or Irish potato. However, when the results from studies 2 and 3 were pooled, the (31 of dasheen (76 (SEM 7)) was significantly greater than that of tannia (55 (SEM 5); P=0(.)015) with potato being intermediate (69 (SEM 6)). We conclude that dasheen and cassava are high-GI foods, whereas the other tubers studied and sadha roti are intermediate-GI foods. Given the regular usage of cassava and dasheen in Caribbean diets we speculate that these diets would tend to be high GI, although this could be reduced by foods such as sadha roti and white yam. The range of GI between the staples is sufficiently large that health benefits may be accrued by replacing high-GI staples with intermediate-GI staples in the Caribbean diet.
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A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
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This study was carried out to establish some physical properties and proximate chemical compositions of taro corms collected from Anamur and Bozyazi in Icel province. Turkey. A total of two taro corms from different sources were evaluated for pH. dry matter, crude protein, crude cellulose unrefined oil, starch, invert sugar, total sugar, ash, Ca, Mg ve K. French fries produced from the corms were evaluated on composition and sensory properties. The samples collected from Anamur and Bozyazi differed in some parameters. Taro corms were rich in starch, magnesium and potassium. Sensory analysis of the products showed no difference between the samples, and taro purees were less liked while french fries were more preferred when compared with those made with potatoes. Taro and its products were recommended as a novel crop and a valuable food source.
Article
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
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The sum of hydrophilic antioxidants of 23 vegetables and 13 fruits commonly consumed in Japan was evaluated by a modified hydrophilic-oxygen radical absorbance capacity (H-ORAC) method. The “typical vegetable” and “typical fruit” in Japan contained hydrophilic antioxidants that are equivalent to 6.95 and 12.23 μmol of Trolox per g of the edible portion, respectively, on average. Hence, the daily intake of hydrophilic antioxidants from vegetables and fruits was estimated to be 4423 μmol Trolox equivalent (TE)/d based on data of the National Health and Nutrition Survey in Japan. However, the biological significance of these antioxidant values has not yet been clarified. To address this issue, our data will provide a foundation for high-quality epidemiological studies aimed at elucidating the relationship between daily intake of antioxidants and health. In addition, the comparison of the results of the H-ORAC assay with those of polyphenol content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was also studied. The H-ORAC values had a strong positive correlation with polyphenol contents (r = 0.956), and were 1.0–18.2-times higher than the antioxidant capacities evaluated by the DPPH assay.
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To evaluate the comparability of the two most common radical scavenging assays using 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, the 50 most popular antioxidant-rich fruits, vegetables and beverages in the US diet were identified and analyzed for their antioxidant capacities, total phenolics and flavonoids content. Spearmans–Rho correlation coefficients were calculated in order to characterize the relationship between antioxidant capacities, total phenolics and flavonoids content. Antioxidant capacity showed a strong positive relationship comparing both assays (ρ=0.949, p
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Digestibility, gelatinization, retrogradation and pasting properties of starch in various cereal, tuber and legume flours were determined. Rapidly and slowly digestible starch and resistant starch were present in I I selected flours. In general, cereal starches were more digestible than legume starches and tuber starches contained a high amount of resistant starch. Thermal and theological properties of flours were different depending on the crop source. (c) 2005 Elsevier Ltd. All rights reserved.
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To address growing research interests and needs, a glycemic index (GI) database was developed for the more than 18,000 foods in the University of Minnesota's dietary data collection software, the Nutrition Data System for Research (NDSR). The primary source of data was current scientific literature with GI selected whenever possible from studies that used the following methodology: North American foods, healthy subjects, and a 2-h glucose response. Two GI numbers were included for all foods, one based on glucose as a reference, and the other, a white bread reference. Assigning indices within a large database also required imputation, because there are relatively few data available from the literature. For database foods that were not a match to foods in the literature, GI was either estimated from similar foods or calculated from available carbohydrate amounts and the GI of ingredients within the food. To evaluate the calculation procedure, GIs were calculated and then compared to known literature values for 102 multi-ingredient foods. A wide range of foods had comparable GIs, while some sweetened dairy products and unsweetened breakfast cereals showed larger GI differences. The GI database provides researchers with a tool to identify low- and high-GI foods and to investigate whether GI or glycemic load (GL) in the diet will influence disease risk factors.
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Taro (Colocasia esculentaL. Schott) flours were prepared from six varieties of taro corms coded as RIN, RIE, CN, CE, KW1 and KW2. Starch yields prepared from the flours varied between 66.5% for KW2 to 86.6% for RIE. The proteins content varied from 2.9% for KW1 to 4.9% for CN in the flours. Taro starch had irregular, polygonal shapes and small granular sizes. A wide variation was observed in the granular diameter of each of the starch samples and between the samples. The amylose contents varied from 14.7 ± 1.64% to 30.85 ± 0.63% as determined by the DSC method. The taro starch contained 0.2–0.6% lipids and 2% ash. The onset gelatinisation temperatures of the taro flours varied from 55.2 to 65.49�C, whereas those of the starches are between 48.08 ± 2.46 for KW2 and 64.37 ± 2.35�C for KW1. Retrogradation of the starches and the flours, as measured by their enthalpy changes, appeared to vary significantly between the varieties. The water absorption capacity varied from 240% to 470% and from 60% to 250% for the flours and starches samples, respectively. Taro flours had higher solubility index than their starch counterparts. Among the varieties, RIN and CE starches had the highest solubility whereas KW1 starch had the lowest. The sorption study also revealed the high ability of the taro flours to absorb water compared to their starch components
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Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
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The catechins, including epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG), and the theaflavins, including theaflavin (TF), theaflavin monogallate (TF-1), and theaflavin digallate (TF-2), were extracted from green tea and black tea, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability, superoxide-scavenging efficiency, and lipid oxidation-inhibition ability of the pure compounds listed above as well as epicatechin (EC), carnosol, carnosic acid, and butylated hydroxytoluene (BHT) were investigated. The DPPH radical-scavenging ability of the catechins was EGCG > ECG > EGC > EC and of the theaflavins was TF-2 > TF-1 > TF. EGCG, ECG, EGC, TF-2, TF-1, and TF showed higher DPPH radical- and superoxide-scavenging abilities than carnosol, carnosic acid, and BHT. EGCG, ECG, EGC, carnosol, and carnosic acid showed higher lipid oxidation-inhibition activity, as measured by the Rancimat method, than BHT and theaflavins.
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The concept of resistant starch (RS) has evoked new interest in the bioavailability of starch and in its use as a source of dietary fiber, particularly in adults. RS is now considered to provide functional properties and find applications in a variety of foods. Types of RS, factors influencing their formation, consequence of such formation, their methods of preparation, their methods of estimation, and health benefits have been briefly discussed in this review.
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Taro corms were cooked in four different mediums (water, tamarind solution, lemon solution, or steam) during 25 min. Changes in hardness, soluble sugars, soluble proteins, degree of gelatinisation (iodine index), degree of cell separation (VICS), resistant starch, total oxalate, absorbance at 280 nm (A280) and 450 nm (A450) were evaluated. The results showed that irrespective of the cooking medium, the hardness, soluble proteins, and resistant starch significantly decreased during cooking while A280, A420, iodine index, VICS and soluble sugars significantly increased. A significant correlation was observed between the hardness and the iodine value, resistant starch, soluble sugars and VICS, suggesting multiple mechanisms involved in the softening of taro corms during cooking. It was observed that steam cooking of the slices induces the highest softening while boiling in water induces the lowest softening of the corms. However cooking in tamarind and lemon solutions induced a bitter and acid taste to the corms. While no consistent change was observed during steaming, significant reduction was observed in the oxalate content during boiling probably due to leaching in boiling solutions and acid hydrolysis.
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For nutritional purposes, starch may be divided into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). These fractions can be determined in vitro by a new analytical technique. Using this classification and technique the digestibility of starch from potatoes processed in various ways has been assessed. Potato starch was highly resistant to hydrolysis by amylase when raw but was rendered rapidly digestible by all conventional cooking techniques. After cooling, cooked potato contained a small proportion of RS formed as the result of processing. Isolated potato starch was rapidly digestible when cooked with water but, when made into biscuits cooked under dry conditions, much of the resistance was retained. Further analysis of the RS showed that, in raw potato and in potato biscuits cooked under dry conditions, resistance to digestion was due to the structure of the starch granules whereas, after cooking with water and cooling, the resistance was mainly attributable to retrogradation of starch.
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Achu is a thick porridge obtained by cooking and pounding taro (Colocasia esculenta) corms and cormels in a mortar. This study was undertaken with the objective of producing precooked taro flour that can be used in the preparation of achu. Taro slices were precooked to times of 0, 20, 45 and 90 min and dried in an air convection oven at varying temperatures of 50, 60, 70 or 80 °C before milling into flour which was then analysed for its water absorption capacity (WAC), water solubility index, emulsion activity and stability, bulk density, foam capacity and least gelation concentration (LGC). Achu made from the flours were equally analysed for their relative penetrometric index, bulk density and colour. The results showed that precooking induced significant (P<0.05) decrease in foam capacity, penetrometric index, and increase in LGC, emulsion stability and WAC. The drying temperature also induces significant reduction in emulsion capacity and stability, penetrometric index, and increase in LGC, WAC. Long precooking time (>45 min) and drying temperature (>60 °C) induced significant reduction of the in-vitro carbohydrate digestibility of taro achu.
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An in vitro procedure to measure the rate of starch digestion in starchy common foodstuffs was developed. A first-order equation that rules the hydrolytic process was found: CC∞ (1−e−kt). Besides an in vivo assay, to calculate the glycemic index (GI), was carried out on thirty healthy volunteers. This is a simple in vitro method that could be used to estimate the metabolic glycemic response to a food. The best correlated value with in vivo glycemic responses was the percentage of starch hydrolysis at 90 min (r= 0.909, p≤0.05, GI1 = 39.21 + 0.803(H90)).
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Some factors present in the starchy foods influence the rate at which the starch is hydrolysed and absorbed in vivo. In order to predict the physiological effects of starchy foods and to complement information of food composition database, the quantification and characterization of the various components in the starch fraction must be evaluated. The contents of total starch (TS), resistant starch (RS), digestible starch (DS), amylose and dietary fibre (DF) were evaluated in 11 starchy foods cooked and cooked/stored (−20°C/30 days—conventional and domestic storage). The in vitro starch hydrolysis, the hydrolysis index (HI), rapidly digestible starch (RDS) and slowly digestible starch (SDS) were also carried out with the same samples. These storage conditions increased the RS content and decreased the HI in all studied foods, and each food showed a specific behaviour in relation to each variable. The high concentration of amylose is not the only fact involved with the starch retrogradation and the formation of RS. Therefore, the complete characterization of the starch fraction of foods subjected to different ways of preparation and storage conditions should be included in the food composition database. The highly significant positive correlation observed between the HI and RDS (y=0.573x −16.671, r=0.907, P⩽0.001, n=22) suggests that the RDS, expressed as dry weight, is an alternative device to predict the digestion of starchy foods.
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Frequent consumption of fruits and vegetables is associated with a lowered risk of cancer, heart disease, hypertension and stroke. This has been attributed to the presence of various forms of phytochemicals and antioxidants present in the foods, e.g. carotenoids and polyphenol compounds including flavonoids and anthocyanins. Seventy Fiji grown fruits and vegetables, and some other commonly consumed products, were analysed for their total antioxidant capacity (TAC), total polyphenol content (TPP), total anthocyanin content (TAT) as well as the major flavonol and carotenoid profiles. These data will be used to estimate the phytochemical and antioxidant intake of the Fijian population and will be a useful tool in future clinical trials.Green leafy vegetables had the highest antioxidant capacity, followed by the fruits and root crops. A number of herbs also exhibited high antioxidant capacity. Ipomoea batatas (sweet potato) leaves have the highest TAC (650 mg/100 g) and are rich in TPP (270 mg/100 g), quercetin (90 mg/100 g) and β-carotene (13 mg/100 g). Moringa oleifera (drumstick) leaves also have a high TAC (260 mg/100 g) and are rich in TPP (260 mg/100 g), quercetin (100 mg/100 g), kaempferol (34 mg/100 g) and β-carotene (34 mg/100 g). Curcuma longa (turmeric ginger) has a high TAC (360 mg/100 g), TPP (320 mg/100 g) and is rich in fisetin (64 mg/100 g), quercetin (41 mg/100 g) and myricetin (17 mg/100 g). Zingiber officinate (white ginger) also has a high TAC (320 mg/100 g) and TPP (200 mg/100 g). Zingiber zerumbet (wild ginger), a widely used herb taken before meals is the richest source of kaempferol (240 mg/100 g).
Article
Sixty-six types of vegetables commonly consumed in Singapore were analysed for their hydrophilic oxygen radical absorbance capacity (H-ORAC), total phenolic content (TPC), ascorbic acid (AA) and various lipophilic antioxidants. A single batch analysis of each vegetable showed that antioxidant composition and concentration varied widely across different vegetables. The vegetables with intense colours typically have high H-ORAC, TPC, AA, and carotenoid contents. Vegetables unique to the Asian market such as matrimony vine (Lycium chinense Miller), coriander, Chinese kale, water spinach and red chilli were consistently ranked high in H-ORAC, TPC, carotenoids and vitamin E levels. Based on consumption data, Chinese Singaporeans appear to have a higher intake of lutein, zeaxanthin, β-carotene, and tocopherols compared to the US population. Overall findings suggest that dark green leafy and brightly-coloured vegetables tend to contain high antioxidants. Our data are useful reference and substantiate many public health agencies’ recommendation to consume more vegetables, particularly the dark green leafy and brightly-coloured varieties.
Article
To compare the blood glucose-lowering effect of a highly viscous fiber blend (VFB) added to a starchy snack on postprandial glycemia between healthy participants and participants with diabetes mellitus. Ten healthy participants (4 men and 6 women, aged 28+/-2.6 years, body mass index [BMI], 24.3+/-0.8 kg/m(2)) and 9 participants with diabetes mellitus type 2 (3 men and 6 women, aged 68+/-3.8 years, BMI 28.8+/-1.2 kg/m(2)) on four separate occasions took either 50 g available carbohydrates as control biscuits, biscuits with 10 g of highly viscous fiber blend, white bread with 12 g of margarine, or white bread alone. Postprandial blood glucose response, glycemic index (GI), and palatability were determined. Mean (95% confidence interval) GI values of the viscous fiber blend biscuits were 26 (16-36) and 37 (27-47) GI units for healthy participants and participants with diabetes mellitus, respectively. These values were significantly lower than those of white bread, white bread with 12 g of margarine, and control biscuits (P<0.001, paired t test) both in healthy participants (GI 100, 108 [57-159], and 101 [44-158], respectively) and participants with diabetes mellitus (GI 100, 103 [79-127], and 94 [78-110], respectively). Viscous fiber blend significantly reduced the glycemic index by 74% (7.4 GI units/g of fiber) in healthy participants and by 63% (6.3 GI units/g of fiber) in participants with diabetes. The GI did not differ between control meals in both healthy participants and participants with diabetes. There were no significant differences in palatability among the types of meals, although participants with diabetes found the viscous fiber blend biscuits more palatable (P=0.002, t test). Viscous fiber blend is a very potent and palatable soluble fiber addition to a starchy snack, which is able to reduce the glycemic response to a similar extent in both healthy participants and individuals with diabetes mellitus. Biscuits with low GI, and possibly other viscous fiber blend fortified starchy foods, may potentially be a useful replacement of high GI snack foods in the diet.
Article
A chemically based classification of dietary carbohydrates that takes into account the likely site, rate, and extent of digestion is presented. The classification divides dietary carbohydrates into sugars, starch fractions, and nonstarch polysaccharides, and groups them into rapidly available glucose (RAG) and slowly available glucose (SAG) as to the amounts of glucose (from sugar and starch, including maltodextrins) likely to be available for rapid and slow absorption, respectively, in the human small intestine. We hypothesize that RAG is an important food-related determinant of the glycemic response. The measurement of RAG, SAG, and starch fractions by an in vitro technique is described, based on the measurement by HPLC of the glucose released from a test food during timed incubation with digestive enzymes under standardized conditions. Eight healthy adult subjects consumed 8 separate test meals ranging in RAG content from 11 to 49 g. The correlation between glycemic response and RAG was highly significant (P < 0.0001) and a given percentage increase in RAG was associated with the same percentage increase in glycemic response. After subject variation was accounted for, RAG explained 70% of the remaining variance in glycemic response. We show the significance of in vitro measurements of RAG in relation to glycemic response in human studies. The simple in vitro measurement of RAG and SAG is of physiologic relevance and could serve as a tool for investigating the importance of the amount, type, and form of dietary carbohydrates for health.
Article
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.