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Effect of Peeling and Cooking on Nutrients in Vegetables
Abstract
Four vegetables brinjal, bitter gourd, colocasia and tomato were subjected for total protein, crude fiber, ash calcium, magnesium, phosphorus, potassium, ascorbic acid and folic acid contents in raw peeled raw cooked and peeled cooked forms. Losses of nutrients due to peeling and cooking were determined. The loss of protein was non-significant during peeling and was significant during cooking except in colocasia. Vegetables lost crude fiber significantly during peeling, cooking caused significant effect only in peeled form, ash reduced significantly during peeling and cooking except in tomato. Four minerals reduced significantly in both peeling and cooking especially in peeled cooking. Vitamins losses were highly significant in both peeling and cooking.
... Frying also appeared to be increasing mineral contents of vegetables as compared to raw but we are not able to find out the reason. However, similar findings have already been reported by Bognar (1998) and Alvi et al., (2003) [12,13] Processed vegetables had reduced amount of protein. ...
... Frying also appeared to be increasing mineral contents of vegetables as compared to raw but we are not able to find out the reason. However, similar findings have already been reported by Bognar (1998) and Alvi et al., (2003) [12,13] Processed vegetables had reduced amount of protein. ...
... However, the losses of crude protein were not significant due to peeling. Similar findings were reported by Alvi et al. and Komolafe and Obayanju [13,14] ...
Nutritional status of two vegetables (Lagenaria siceraria and Citrullus vulgaris var. fistulosus) was estimated after different cooking treatments with and without peeling. Crude fiber, ash, minerals (Na + , K + and Ca +2) and proteins were calculated through different methods. Results showed that losses of nutrients were considerably high due to microwave cooking and boiling while losses observed after frying were comparatively lesser. ANOVA revealed statistically significant results for both the specimens.
... Vegetables are a major source of minerals and vitamins [32] and are affected by the handling method during preparation. Eighty four percent of the caregivers indicated that they soak vegetables for less than five hours before cooking. ...
... Most (82.2 %) of the caregivers indicated that they do not blanch vegetables, whilst the remainder (17.8 %) indicated that they do. Methods, temperature and duration of cooking may significantly affect the nutritive value of the cooked vegetables [32]. Nutrients such as ascorbic acid and folic acid, which are susceptible to oxidation are oxidized by quickened cooking methods. ...
... Minerals and proteins and flavor characteristics are distressed by high temperature, resulting to altered qulity attributes of cooked vegetables. Excessive cooking may also cause an adverse effect on the digestibility of the vegetables [32]. ...
Caregiving tasks involve a wide range of services given by the caregivers including general management of the household activities. This study was aimed at examining the nutrition knowledge and food handling practices of household caregivers in rural communities within Mandeni Municipality located in the rural part of KwaZulu Natal (KZN). Data collection was done through structured questionnaires that contained predetermined questions. The study probed on the socioeconomic background of the household caregivers. Questions also delved on the nutrition knowledge and the food handling practices of caregivers. The results of the study revealed that women were the main caregivers in the households. Furthermore, a larger percentage of the households depend on social grants for source of income that must care for up to more than ten members of the family. Caregivers demonstrated cooking methods such as boiling, grilling, roasting and stewing as the most preferred cookery methods for meat, poultry, fish and eggs. Boiling vegetables proved the most popular method among caregivers. The study established that the household caregivers have acquired nutrition knowledge from different sources, with less contingent indigenous sources of information. More still needs to be done to empower keepers for effective caregiving.
... The reduction of ash content after skin removal was about 49.33% and it almost half of the loss. [25] reported that ash content reduced significantly after peeling in raw Brinjal, Bitter gourd, and Colocasia by 18.96%, 11.11%, and 13.21%, respectively. ...
... Hence, it is apparent from the data that the reduction values of C2 from C1 due to peeling caused a 63.63% loss of crude fiber. A similar finding was reported by a prior study, in which peeling caused the 32.58% loss of crude fiber in the tuber of Colocasia [25]. ...
In this study, physical and chemical properties (dry matter, ash, moisture, protein, fat, fiber, carbohydrate, starch, amylose, and vitamin C) of sweet potato tuber and flour of Anggun 1 cultivar were evaluated at different conditions. During peeling, the tuber and flour were processed subjected to three different conditions, which were unpeeled tubers (C1), peeled tubers (C2), and skin of tuber only (C3). From the results, the highest (p < 0.05) dry matter was observed in C1 while higher contents of ash, moisture, and protein were found in C3. Regarding the fat and vitamin C content, no significant differences (p > 0.05) were found between each condition. The highest fiber, carbohydrate, and amylose content (p < 0.05) were found in C1. The C1 and C2 reflected significantly higher (p < 0.05) starch content. Overall, these results provide important information about the peeling effect on the physical and chemical properties of Anggun 1. The information could be used as adding value to healthy food in the Malaysian diet due to the nutritional value of sweet potato.
... Moisture loss (%) The highest value of fiber content was noted in BP and CP followed by FP as compared to control. The present work on quality attributes of processed and stored fruits and vegetables are stable throughout storage period is also agreed with Shahnaz et al. (2003) and Rickman et al. (2007). Fig. 1 (a,b,c,). ...
... The ash content is an amount of the essential minerals found in the food (Lewu et al. 2009). Data relating to the ash (Fig. 1c) Shahnaz et al. (2003). Fig. 2 (a,b,c,d,e). ...
Watercress (Nasturtium officinale R. Br.) is a leafy vegetable belong to family Brassicaceae. It is used as raw and processed form in our area. But this vegetable has a short postharvest life. Keeping in views this study was deliberate to evaluate the effect of blanching and cooking with the combination of polyethylene bags on postharvest life of stored watercress vegetables at freezing temperature. The physico-chemical attributes i.e. moisture loss, crude fibre, ash content, titratable acidity (TA), pH, total sugar (TS), ascorbic acid, β-carotene and sensory characteristics like colour, texture, taste, flavour and overall acceptability were studied at an interval of 5 days (1 st , 5 th , 10 th , 15 th , 20 th day) during storage. All of the treatments had shown a highly significant effect (p<0.05) on physcio-chemical and sensory parameters of vegetables. However, among all treatments blanching + polyethylene bag was proved most effective in the retention of crude fibre, ash content, ascorbic acid, β-carotene and sensory parameters i.e texture, taste and flavor. The treated vegetable have increased storage life up to 20 days as compared to control which was un acceptable after 7 th day of the storage. The results suggested that blanching + polyethylene bags with freezing temperature might be helpful to increase the storage life of watercress vegetables for distant marketing.
... It is evident from the data that however, there was difference in values for crude fibre among different treatments but statistically it was non-significant. The results on the losses are supported by the findings of Alvi et al. (2003) in four vegetables viz. brinjal, bitter gourd, colocasia and tomato used as raw and cooked (peeled and unpeeled). ...
... This escalation may be due, in part, to a greater awareness of the beneficial aspects of eating raw vegetables, as it is known that cooking vegetables can destroy critical nutrients. For example, the concentration of ascorbic acid, folic acid and Mg in a tomato is significantly diminished during cooking (19) . Furthermore, the amount of ascorbic acid in raw broccoli, spinach and lettuce is greater than that found in cooked vegetables, particularly in methods of steaming or microwaving (20) . ...
Vegetables are an important source for the essential vitamins and minerals that are necessary for optimal health. This research investigated changes in vegetable intake over time in the Korean population from 1998 to 2017, focusing on preparation methods of vegetables and location of consumption. This cross-sectional study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) that was established in 1998 to assess the health and nutritional status of the South Korean population. This research utilized information from 1998 to 2017 which is the extent of all available KNHANES data. Vegetable consumption was grouped, according to preparation methods and common eating locations. Both crude and age-standardized means of vegetable intake were derived via a 24-hour dietary recall. All participants who completed a 24-hour dietary recall survey were selected for the analyses. This included 109,220 individuals (49,069 men and 60,151 women) over the course of 20 years of the KNHANES. Total vegetable intake decreased over time ( p for trends <0.001), specifically, steamed and salted vegetables ( p for trends <0.001). In contrast, Koreans consumed noticeably more raw vegetables from 1998 to 2017 ( p for trends <0.001). Vegetable intake at home significantly declined ( p for trends <0.001), while that eaten at restaurants or outside the home increased greatly ( p for trends <0.001). Over 20 years, Koreans have ingested decreasing amounts of vegetables, but the intake of raw vegetables has escalated. However, the location of vegetable consumption has changed, with an increase at both restaurants and outside the home (≍ 70.0%).
... and light red 1.00±0.00% which was within the range of 0.70 -3.25% when compared with the reports obtained by Onifade et al. (2013); Alvi et al. (2003); Adebooye et al. (2006); Olaniyi et al. (2010). All samples used contain a considerable amount of fibre in varying quantities. ...
Tomatoes (Lycopersicon Esculentum Mill) are well known vegetable that contains vitamins, antioxidants and other health beneficial substances. This study evaluates quality (vitamin C, protein, fat, crude fibre, ash content, moisture content, carbohydrate, weight loss, firmness and antioxidant activity) and shelf-life of tomatoes under refrigerator storage method at 10 o C using three maturity stages (breaking stage, pale red stage and light red stage) of 'Beefmaster HYBRID VFNASt' tomato varieties cultivated in a greenhouse, harvested and stored for 18 days. The physical qualities were determined during storage whilst antioxidant activity (lycopene and carotenoid concentrations) was evaluated before and after 18 days of storage. The results obtained shows that before storage; tomatoes has high moisture content (95.36%) and protein content (1.04%) at breaking stage, highest value of fat content (0.59%) and crude fibre content (1.13%) was recorded at pale red stage, while the highest ash content (0.43%), carbohydrate (3.17%), carotenoid content (0.3272 mg/g), lycopene content (0.7309 mg/g) and vitamin C content (0.1268 mg/g) was recorded at light red stage. An increase was observed in the antioxidant activities and proximate composition after 18 days of storage. The concentration of vitamin C content of tomato fruit after storage compare with the fresh sample is significantly (p<0.05) depends on maturity stages of the tomato fruit. The highest nutritional value (quality and shelf-life) was recorded for breaking stage. The results obtained also shows that carotenoid and vitamin C contents of the tomato fruits slight increase at the end of the storage period in breaking stage and this increase is significantly depends on maturity stage. It was observed that ripening stage has significant influence on the nutritional values which indicate that the ideal maturity stage to maintain optimal shelf life and nutritional quality is breaking stage of tomato fruit which is the most suitable for storage.
... and light red 1.00±0.00% which was within the range of 0.70 -3.25% when compared with the reports obtained by Onifade et al. (2013); Alvi et al. (2003); Adebooye et al. (2006); Olaniyi et al. (2010). All samples used contain a considerable amount of fibre in varying quantities. ...
Tomatoes (Lycopersicon Esculentum Mill) are well known vegetable that contains vitamins, antioxidants and other health beneficial substances. This study evaluates quality (vitamin C, protein, fat, crude fibre, ash content, moisture content, carbohydrate, weight loss, firmness and antioxidant activity) and shelf-life of tomatoes under refrigerator storage method at 10 o C using three maturity stages (breaking stage, pale red stage and light red stage) of 'Beefmaster HYBRID VFNASt' tomato varieties cultivated in a greenhouse, harvested and stored for 18 days. The physical qualities were determined during storage whilst antioxidant activity (lycopene and carotenoid concentrations) was evaluated before and after 18 days of storage. The results obtained shows that before storage; tomatoes has high moisture content (95.36%) and protein content (1.04%) at breaking stage, highest value of fat content (0.59%) and crude fibre content (1.13%) was recorded at pale red stage, while the highest ash content (0.43%), carbohydrate (3.17%), carotenoid content (0.3272 mg/g), lycopene content (0.7309 mg/g) and vitamin C content (0.1268 mg/g) was recorded at light red stage. An increase was observed in the antioxidant activities and proximate composition after 18 days of storage. The concentration of vitamin C content of tomato fruit after storage compare with the fresh sample is significantly (p<0.05) depends on maturity stages of the tomato fruit. The highest nutritional value (quality and shelf-life) was recorded for breaking stage. The results obtained also shows that carotenoid and vitamin C contents of the tomato fruits slight increase at the end of the storage period in breaking stage and this increase is significantly depends on maturity stage. It was observed that ripening stage has significant influence on the nutritional values which indicate that the ideal maturity stage to maintain optimal shelf life and nutritional quality is breaking stage of tomato fruit which is the most suitable for storage.
... reductions in the contents of K, Ca, Na, Mg, P and Fe in the flour prepared from the boiled nuts when compared with their values in the flour prepared from the raw nuts could be attributed to leaching out of the minerals into the boiled water (Kiremire et al., 2010;Musa and Ogbadoyi, 2012). This observation is in line with the findings of Augustin et al. (1981), Alvi et al. (2003) and Oboh (2005) that various conventional food processing techniques such as blanching and cooking cause a significant decrease in the mineral content of the vegetables. Fagbemi (2007) similarly reported that flour from boiled pumpkin seeds contained less K, Na, Mg, P, Fe and Zn than flour from the raw pumpkin seeds. ...
In the current study, the effect of boiling and roasting conophor nuts on the nutrient and anti-nutrient contents in the flour was investigated. The proximate analysis showed that the flour from raw nut is rich in protein content (54.49%). Flours from the boiled nuts and roasted nuts contained lower protein, fat and ash contents, but higher crude fibre, carbohydrate and caloric value than their values in the flour from raw nut. Boiling and roasting of the nuts led to reductions in the Ca, Na, Mg, Fe and Zn contents in the conophor nut flour when compared with their values in the flour from raw nut. "Flour from roasted nuts had significantly (p<0.05) higher K and P contents than their values in the flours from raw and boiled nuts". Boiling and roasting of the nuts significantly (p<0.05) reduced the levels of HCN, oxalate, phytate, tannins and trypsin inhibitor in the flour when compared with their values in the flour from raw nut. Boiling was more effective in the reduction of the anti-nutritional factors than roasting.
... Alvi et al. investigated the efects of peeling on tomato, which contains vitamins A, C, and E, as well as various phytochemical compounds including lycopene, and found a reduction of 18.3% in iber, 25.4% in calcium, 32.6% in magnesium, 6.4% in phosphor, 2.9% in potassium, 28.9% in ascorbic acid, and 17.2% in folic acid after peeling [130]. ...
... Various cooking methods are used based on convenience and taste preference rather than nutrient retention. Some cooking methods may oxidize antioxidants [72] and affect the vegetable nutrient retention. It is therefore important to choose a cooking method that leads to optimal nutrient retention and bioavailability [73]. ...
African leafy vegetables (ALVs) are mostly gathered from the wild, with few selected species being cultivated, usually as part of a mixed cropping system in home gardens or smallholder plots. They have important advantages over exotic vegetable species, because of their adaptability to marginal agricultural production areas and their ability to provide dietary diversity in poor rural communities. Despite their significance in food and nutrition security, there is limited availability or access to these crops leading to underutilisation. The objective of this review was to document the state of utilisation and production of ALVs in South Africa. A qualitative systematic approach review of online sources, peer reviewed papers published in journals, books and other publications was conducted. There is lack of suitable production systems, innovative processing, and value-adding techniques that promote utilisation of ALVs. Furthermore, there is a perception that ALVs are food for the poor among the youth and urban folks, while, among the affluent, they are highly regarded as being nutritious. To promote ALVs from household consumption and commercialisation, further research on agronomy, post-harvest handling, storage and processing is required in South Africa.
... Cooking methods used are mainly based on convenience and taste preference rather than nutrient retention [12]. Some cooking methods such as those used by the communities in this study may oxidize antioxidants [13] and affect the vegetable nutrient retention. ...
... The level of mineral content (K, P, and Mg) was lower in cooked and sliced leaves when compared to sun-dried and unsliced samples. This is in line with the observations of Bakr and Gawish [19], Shahnaz et al. [20], and Oboh [21] that various conventional food processing techniques (cutting, bleaching, cooking, etc.) cause a decrease in the mineral content of vegetables. Losses of the mineral elements during boiling or cooking are generally attributed to the leaching of the cell content including minerals [19]. ...
The effects of various processing methods on the proximate composition and dieting of Amaranthus hybridus and Amaranthus cruentus from West Cameroon were investigated in this study. Both amaranths leaves were subjected to same treatments (sun-dried and unsliced, sliced and cooked), milled, and analysed for their mineral and proximate composition. Thirty-Six Wistar albino rats of 21 to 24 days old were distributed in six groups and fed for 14 days with 10% protein based diets named D0 (protein-free diet), DI (egg white as reference protein), DII (sun-dried and unsliced A. hybridus), DIII (cooked and sliced A. hybridus), DIV (sun-dried and unsliced A. cruentus), and DV (cooked and sliced A. cruentus).The protein bioavailability and haematological and biochemical
parameters were assessed in rats.The results showed that K, P, Mg, Zn, and Fe had the higher content in both samples regardless of processing method.The sun-dried and unsliced A. cruentus contained the highest value of crude protein 32.22 g/100 g DM (dry matter) while the highest crude lipid, 3.80 and 2.58%, was observed, respectively, in sun-dried and unsliced A. hybridus and cooked and sliced A. cruentus. Cooked and sliced A. hybridus and A. cruentus contained high crude fiber of 14 and 12.18%, respectively. Rats fed with diet DIII revealed the best protein bioavailability and haematological parameters whereas 100% mortality rate was recorded with group fed with diet DIV. From this study, it is evident that cooked and sliced A. hybridus and A. cruentus could play
a role in weight reduction regimes.
... The result agreed with the report of [31] that squeeze washing and cooking caused significant (P=.05) reduction in the levels of some minerals in the vegetables. Also the observed reduction in the mineral content in this study agrees with the results of some other studies [32][33][34][35]that various conventional food processing techniques (blanching and cooking) caused a significant (P=.05) decrease in the mineral content of various samples analyzed. Losses of mineral elements during pretreatment were attributed to the leaching of the cell content including minerals during cooking [32]. ...
... These values represent 193, 133 and 217 % of the DRI for vitamin C assuming a daily portion of 150 g (see online Supplementary Table S1). However, up to 89 % of the vitamin C in tomatoes is lost by cooking, reducing its nutritional value to 21 % of the DRI (78) . Transgenic potatoes have been produced yielding 915 mg of vitamin C/g fresh weight, which is equivalent to 133 % of the DRI for vitamin C assuming a daily portion of 130 g (79) . ...
The biofortification of staple crops with vitamins is an attractive strategy to increase the nutritional quality of human food, particularly in areas where the population subsists on a cereal-based diet. Unlike other approaches, biofortification is sustainable and does not require anything more than a standard food-distribution infrastructure. The health-promoting effects of vitamins depend on overall intake and bioavailability, the latter influenced by food processing, absorption efficiency and the utilisation or retention of the vitamin in the body. The bioavailability of vitamins in nutritionally enriched foods should ideally be adjusted to achieve the dietary reference intake in a reasonable portion. Current vitamin biofortification programmes focus on the fat-soluble vitamins A and E, and the water-soluble vitamins C and B9 (folate), but the control of dosage and bioavailability has been largely overlooked. In the present review, we discuss the vitamin content of nutritionally enhanced foods developed by conventional breeding and genetic engineering, focusing on dosage and bioavailability. Although the biofortification of staple crops could potentially address micronutrient deficiency on a global scale, further research is required to develop effective strategies that match the bioavailability of vitamins to the requirements of the human diet.
... The moisture content ranged from 90.86% to 95.04% with the mean value of 92.72%. The levels of various macro-and micro-minerals studied among the 32 eggplant germplasm accessions were consistent with the levels reported earlier (ALVI et al., 2003; RAIGON et al., 2008). Variability plays an important role in crop breeding programs. ...
Eggplant, Solanum melongena L. is one of the most popular and
major vegetable crops grown in South Asia and other parts of the
world. It is an important source of plant-derived nutrients like
minerals, available throughout the year and popular among the
poor. Thirty two morphologically diverse eggplant germplasm accessions
were analyzed for macro- and micro-minerals. Significant
differences in the mineral content among the germplasm accessions
were detected. Potassium and magnesium ranged from 177.19
to 274.48 mg and 6.25 to 18.34 mg/100 g fresh weight (FW),
respectively. Copper, iron and zinc ranged from 0.024 to 0.178,
0.170 to 0.846 and 0.073 to 0.233 mg/100 g FW, respectively.
Phenotypic co-efficient of variation and genotypic co-efficient of
variation were high for the minerals studied except potassium. High
broad sense heritability (84.44-97.07%) indicated the presence of
additive gene effects. Significant positive correlation were found
between zinc with potassium (r=0.397), magnesium (r=0.439) and
copper (r=0.409). Overall, two germplasm accessions IC090785
and IC383102 have been identified as rich sources for all minerals
studied, which could be utilized further in breeding programme for
developing mineral-rich varieties of eggplant.
... Pusa Upkar and Pusa Purple Long, respectively. The levels of potassium and magnesium were consistent with the levels reported earlier (Chen and Li, 1996;Alvi et al., 2003;Gopalan et al., 2007;Raigon et al., 2008). ...
Development of mineral-rich varieties of eggplant (Solanum melongena L) is a breeding objective, increasingly important to achieve eradication of malnutrition. In the present study, 25 morphologically diverse eggplant genotypes comprising 20 germplasm accessions and 5 commercial varieties were analyzed for dry matter, potassium, magnesium, iron, copper and zinc content on a fresh weight (FW) basis. Significant differences in the mineral composition among the genotypes were detected. Germplasm accessions were found to be rich in mineral composition as compared to commercial varieties. Dry matter content ranged from 6.03 to 9.14 g/100 g FW. The macro-minerals such as potassium and magnesium ranged from 159 to 272 mg and 5.15-20.4 mg/100 g FW, respectively. The micro-minerals such as copper, iron and zinc ranged from 0.0453 to 0.144 mg, 0.199-0.813 mg, and 0.0778-0.270 mg/100 g FW, respectively. Potassium and iron rich genotypes, namely IC090146, IC249323 and IC090146 could be exploited as potential donors for developing mineral-rich eggplant varieties.
... The present results regarding calcium, magnesium, phosphorus, iron, zinc and potassium are in close agreement with those of previous studies. 18,19,24 It is evident from the literature that calcium, magnesium, iron, zinc and some other minerals become less available to plants grown under sodic conditions, and consequently the concentrations of sodium, chloride and carbonate become higher in such plants. The accumulation of excess sodium, leading to poor soil permeability, increases the pH and decreases the availability of nutrients such as calcium, magnesium and zinc. ...
BACKGROUND: The use of sodic water for crop irrigation decreases the availability of nutrients such as nitrogen, calcium, magnesium and zinc to plants and harms crop yield and quality. Crops irrigated with sodic water have been utilised in various product formulations. Gypsum and farmyard manure (FYM) are known to provide good soil amendment under sodic water irrigation. This research was therefore conducted to study the variation in nutrient composition of tomato products prepared from tomatoes irrigated with canal water (control) and those irrigated with sodic water treated with gypsum and FYM at two levels, i.e. 50% neutralisation of sodicity (G1F2) and complete neutralisation of sodicity (G2F2).
RESULTS: The contents of protein, fat, crude fibre, ash, carbohydrate and total soluble sugars in three types of tomato product were in the ranges 1.08–1.68, 0.20–0.31, 0.43–1.07, 0.83–1.06, 6.17–7.22 and 2.32–4.81 g kg−1 respectively. Tomato products prepared from tomatoes irrigated with G1F2-treated water contained significantly (P < 0.05) less protein, fat, crude fibre, dietary fibre, calcium, magnesium, phosphorus, potassium, iron, zinc and sulfate but more ash, carbohydrate, total soluble sugars, oxalic acid, polyphenols, sodium, chloride and bicarbonate than those prepared from tomatoes irrigated with canal water and G2F2-treated water.
CONCLUSION: The results showed that tomato crops irrigated with sodic water treated with gypsum and FYM to varying extent were effective in maintaining and improving the nutrient composition of various tomato products. Copyright
Cooking at home has experienced a decline in many countries since the mid-20th century. As rates of obesity have increased, there has been an emphasis on more frequent home cooking, including its incorporation into several food-based dietary guidelines around the world as a strategy to improve dietary quality. With the recent trend towards the adoption of diets richer in plant-based foods, many consumers cooking at home may now be cooking plant foods such as vegetables, potatoes and pulses more often. It is, therefore, timely to explore the impact that different home cooking methods have on the range of nutrients (e.g. vitamin C and folate) and bioactive phytochemicals (e.g. carotenoids and polyphenols) that such plant foods provide, and this paper will explore this and whether advice can be tailored to minimise such losses. The impact of cooking on nutritional quality can be both desirable and/or undesirable and can vary according to the cooking method and the nutrient or phytochemical of interest. Cooking methods that expose plant foods to high temperatures and/or water for long periods of time (e.g. boiling) may be the most detrimental to nutrient content, whereas other cooking methods such as steaming or microwaving may help to retain nutrients, particularly those that are water-soluble. Dishes that use cooking liquids may retain nutrients that would have been lost through leaching. It may be helpful to provide the public with more information about better methods to prepare and cook plant foods to minimise any nutrient losses. However, for some nutrients/phytochemicals the insufficient and inconsistent research findings make clear messages around the optimal cooking method difficult, and factors such as bioaccessibility rather than just quantity may also be important to consider.
The effect of peeling and boiling process was investigated on nutrients and health-promoting compounds of amadumbe (Colocasia esculenta), carrots (Daucus carota), sweet potatoes (Ipomoea batatas) and potatoes (Solanum tuberosum). The results indicated that peeling and boiling led to significant reduction of nutrients (total soluble starch, total soluble protein, crude fibre) and health-promoting compounds (flavonols, anthocyanin and phenolic acid). Peeling effects on nutrient content did not yield similar outcome (increase and decrease). Carrots showed insignificant loss of total soluble starch after peeling and major loss was observed after boiling. Amadumbe shows substantial loss of fibre after peeling, peels yielding 42.38% and edible part yielding 8.31% compared to all of the analysed vegetables. Health-promoting compounds were reduced significantly peeling and boiling process. The nutrient and phytochemical compounds in the peels of the various vegetables depends on method of peeling. Fourier-Transform Infrared Spectroscopy (FT-IR) bands evidenced the presence of nutrients and health-promoting compounds in studied vegetables. Keywords: Boiling; Flavonols; Health promoting compounds; Nutrients; Peeling; Phenolic acid
Abstract
The present study was conducted to prepare and preserve persimmon pulp using different preservation methods along with their evaluation for quality and storage stability. The maximum pulp recovery of 88.30% was obtained by hot pulping of persimmon fruits with peel (T3). T3 treatment selected for further studies on the basis of higher sensory scores possessed 0.61 mg/100 g β-carotene, 8.71 mg/100 g, ascorbic acid, 2.91% crude fibre, 6.41 mg/100 g total phenols, and 62.35% antioxidant activity. The preservation of pulp reflected that the persimmon pulp of treatment T1 (pulp + KMS @ 2,000 ppm in glass jars) retained higher ascorbic acid, β-carotene, total phenols, and antioxidant activity during 6 months of storage period. Henceforth, it
is concluded that ripe Hachiya persimmon which otherwise is processed to a limited extent, can be successfully converted into pulp and utilized in various products to improve their nutritional quality.
Practical applications
Persimmon is highly perishable climacteric fruit that may deteriorate quickly when stored at ambient temperature. The fruit, even in convenient storage conditions, has a limited shelf life compared with other fruits. Therefore, after harvesting, a significant amount of mature persimmons should be processed into certain products to preserve the fruit's bioactive components and maintain overall quality. The lack of consistent information on the storage and transport factors leads to losses at the end of production process as well as during the marketing of the fruit. These losses are due to excessive ripening, loss of firmness, rot, and peel browning. But processing of
persimmon is a challenge owing to its mushiness when ripe as it is a climacteric fruit. Henceforth, various methods are employed to extract pulp in order to get the maximum yield and retain nutritional and functional quality.
Objective: The study was designed to determine the frequency, awareness, treatment and control of high blood pressure among the bank employees of Bahawalpur City. Methods: It was an observational, crost-sectional study, carried out by the Department of Cardiology, BVH, Bahawalpur. The study was done from 1st December 2006 to 22nd September 2007. A sample of 188 bank employees working in different banks was taken by convenience sampling technique. Bankers of all ages and both sexes were included and those absent at the time of visits and temporary trainees were excluded. The subjects were interviewed and examined according to Equipment, Condition of patient and Techniques (ECT) recommendations as laid down by US JNC 7th report. The data was collected on a questionnaire and was analyzed manually. Results: Frequency of hypertension in bank employees was 40.96%. Almost half (51.94) of the hypertensives were aware of their disease and the other half were screened during this study. Out of 40 diagnosed patients of HTN, only 23 (57.5%) were taking anti-hypertensive therapy and among those, only 14 (60.87%) were having adequate control of their blood pressure. Hypertension was found to be more frequent among males as compared to females. Other associated risk factors were advancing age, BMI >27, family history of hypertension, tobacco smoking and lack of physical exercise. Conclusion: The study shows a high frequency, low awareness, bad treatment compliance and improvable control of hypertension among the bank employees of Bahawalpur City.
Present study deals with the nutritional value of an aquatic legume, Neptunia prostrata (Lamk.) Baillon, commonly used as shoot vegetable in this part of North East India. Young shoots are used as vegetable in different forms of recipes of tribal and rural communities.The utility of the vegetable as good source of protein and total amino acids with low level of phenolics and sugar clearly indicated its significance as useful health diet and alternative food supplement to the common people. Market economy of the vegetable also highlights its resource potential.
Papaya fruits are commonly used throughout the year both as table fruit and vegetable purpose. Shelf life of the fresh (green) and ripen fruit is very less due to its high water content. Osmotic dehydration of the mature green fruits to produce papaya tuti fruiti is an important alternative to minimize post harvest losses. Moreover, the demand on ready to use dehydrated products is fast increasing throughout the world with the increase in population. The osmotic dehydrated papaya tuti fruiti was prepared with different slice thickness (2-10 mm). The process parameters considered were slice thickness (2-10 mm) and blanching duration (0-20 min) followed by immersion of slices to 40 and 70°B sugar solutions containing 0.05%, potassium meta bisulphate (KMS) and 0.1% citric acid respectively for 1 and 2 h dip at warm condition (80°C). Response surface methodology (RSM) design was considered for this experiment and final products were evaluated for its nutritive value and organoleptic quality. The optimum product qualities in terms of ascorbic acid loss (30.38%), hardness (1.67 kg) and overall acceptability (7.8) were obtained at slice thickness of 7.8 mm and blanching time of 13.6 min.
The nutritionists' interest in leaf vegetables including Hibiscus sabdariffa stems from their rich contents of essential amino acids, vitamins and minerals which are needed for normal metabolic activities of the body. Vegetables are also good sources of dietary fibres that are important for bowel movement. However, the presence of some inherent anti nutrients and toxic substances in vegetables has been a major obstacle in harnessing the full nutritional benefits. It is against this background that this research was conducted to determine the effect of some processing methods on the antinutrients (soluble and total oxalates), toxic substances (cyanide and nitrate) and some micronutrients which include vitamin C, P-carotene (provitamin A) and mineral elements (Fe, Mg, Zn, Na and K) in Hibiscus sabdariffa. The processing methods include boiling (vegetable leaves were boiled in distilled water for 5 and 10 min) and sun drying. Results obtained showed that the cyanide, nitrate and soluble contents in fresh vegetable sample are within the tolerable level and they can be well tolerated in the meals. However, the total oxalate content in the vegetable is high enough to induce oxalate toxicosis. All the processing methods significantly (p<0.05) reduced the antinutrients and toxic substances in Hibiscus sabdariffa except that the reduction in soluble and total oxalate with sun drying was not significant (p>0.05). Boiling methods reduced these toxic substances significantly (p<0.05) more than sun drying. The antinutrients and toxic substances generally decreased with boiling time. These post-harvest treatments also reduced vitamin C content significantly (p<0.05) in Hibiscus sabdariffa. Boiling method retained more of the vitamin compared to sun drying. P-carotene levels increased in the boiled vegetable leaves, while its content was reduced in sundried leaves. However, boiling beyond 5 min led to significant (p<0.05) reduction of P-carotene levels in the vegetable. Mineral elements (Fe, Cu, Mg, Na and K) decreased significantly (p<0.05) with boiling in Hibiscus sabdariffa; however sun drying had no significant effect on the mineral contents. The result concludes that moderate boiling significantly reduces the levels of antinutrients and toxic substances while still conserve some micronutrients in amounts sufficient to meet our dietary requirements.
Processing and cooking conditions cause variable losses of vitamins. Losses vary widely according to cooking method and type of food. Degradation of vitamins depends on specific conditions during the culinary process, e.g., temperature, presence of oxygen, light, moisture, pH, and, of course, duration of heat treatment. The most labile vitamins during culinary processes are retinol (vegetable boiling, 33% retention), vitamin C (the most damaging factors are cooking and oxidation), folate (leaching into the cooking water, 40% retention), and thiamin (cooking, retention 20-80%). Niacin, biotin, and pantothenic acid are quite stable, but information on some vitamins, especially vitamins D and K, is incomplete. The percentage losses of some nutrients in foods after cooking treatment were frequently reported: not continual changes during heat treatment, only modifications at the beginning and after heat treatment. Changes of nutrients in food during the culinary process have not yet been sufficiently investigated. A few authors have attempted to summarize the kinetic data which can be used to describe the time-temperature effect on nutrients. (c) 2005 Elsevier Inc. All rights reserved.
Bitter gourd (Momordica charantia) were analyzed for their major nutrient contents as well as Vitamin C, minerals and phytochemical constituents. The selected varieties were Charantia C.B. Clarke, Muricata (Willd.), Hybrid green and Hybrid white karala. The result revealed the presence of nutrient constituent among the varieties comprising Total sugar (0.114±0.01% to 0.22±0.02%), Starch (0.74±0.01% to 5.3±0.04%), Total protein (1.17±0.01% to 2.4±0.02%), Fat (0.3±0.02 to 0.8±0.02%) and Vitamin C (9.41±0.26 to 13±0.57mg%). This vegetable is good source of minerals such as Mg, Ca, S and Cu. The fruits contained calcium (0.55±0.30 to 7.0±0.25 mg%) and sulpher (44.9±0.38 to 72.4±0.51 ppm). All the varieties were found to contain tannin, flavonoids, terpenoids, cardiac glycosides, triterpin and sterol, resin, amino acid and phenolic compounds except coumarin and free anthraquinone. Based on the findings from this study, bitter gourd (Momordica charantia), although a bitter known vegetables but has enormous nutritional potentials.
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