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Acai pulp addition improves fatty acid profile and prebiotic viability in yogurt
Abstract
The effects of açai pulp addition and different probiotic bacteria on the fatty acid profile of stirred yoghurt were examined. Skim milk was divided into two groups: one containing açai pulp and another without the fruit. Batches were inoculated with yoghurt starter culture and divided into five groups according to probiotic addition. Counts of viable microorganisms were measured at days 1, 14 and 28 of cold storage. Fatty acid profile was determined by gas chromatography at day 1. Açai pulp favoured an increase in Lactobacillus acidophilus L10, Bifidobacterium animalis ssp. lactis Bl04 and Bifidobacterium longum Bl05 counts at the end of 4 weeks of cold storage. This study demonstrated that açai pulp addition increased monounsaturated and polyunsaturated fatty acid contents in probiotic yoghurt and enhanced the production of α-linolenic and conjugated linoleic acids during fermentation of skim milk prepared with B. animalis ssp. lactis Bl04 and B94 strains.
... Pasteurized whole milk (3.25%), purchased from a local market, was heated at 85C for 15 minutes, cooled down to 42C in a water bath and transferred into 50 mL-sterile test tubes. The starter cultures, probiotics, and 4% WB were added and incubated at 42C until the yogurt reached ~ pH 5.0 (Santo et al., 2010). All treatments were done in triplicates. ...
... All tubes were incubated at 42º C for fermentation and pH was measured after 4 h and 1 h thereafter. When the pH reached approximately 5, all tubes transferred were stored at 4 º C (Santo, et al., 2010). On days 1, 7, 14, 21 and 28, total microbial counts were carried in triplicate for each batch at different dilutions; four serial dilutions of 1 to 10. ...
... On days 1, 7, 14, 21 and 28, total microbial counts were carried in triplicate for each batch at different dilutions; four serial dilutions of 1 to 10. An aliquot (5 μL) from each dilution was plated on MRS agar dishes using a spread plate method and incubated at 37°C for 24 h (Santo, et al., 2010). ...
The potential of wheat bran (WB) addition as a prebiotic source were demonstrated using yogurt with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis). Yogurts (with 4% WB) were significantly (P < 0.05) different in total bacterial counts (9.1 log CFU/mL), and total titratable acidity % (TTA, 1.4%) compared to controls during 28 days cold storage (4°C). Additionally, WB-total dietary fiber contents and their bound phenolic profiles were investigated as well as the antioxidant activity of WB-water extractable polysaccharides (WEP) was studied. HPLC analysis of alkaline hydrolyzed DF fractions showed that insoluble DF had higher phenolic acids (84.2%) content than soluble DF (15.8%). Also, crude-WEP showed stronger antioxidant activity compared to purified-WEP with an ORAC of 71.88 and 52.48 µmol TE/g, respectively. Here we demonstrate WB has potentials as a source of prebiotics, which may have the potentials for functional foods and nutraceutical applications.
... Prebiotics are food ingredient that offered several beneficial effects for health, namely enhanced bioavailability of mineral, stimulated activity and growth of profitable live microorganisms in the colon and interfering with pathogen microorganisms in the gastrointestinal tract of host (Aryana and McGrew 2007). Numerous researches have been published on the enrichment of probiotic yoghurt with various stimulating supplements identified as 'prebiotic' which enhance the probiotic growth and survival (do Espírito Santo et al. 2010. The desired growth and activity of lactic acid bacteria with cereals bring to mind that incorporation of probiotics with cereal substrates under controlled conditions in various foods. ...
... Surprisingly, IWG yoghurts containing L431 and L20079 seemed a significantly higher pH (p \ 0.05) compared with their respective controls without IWG (Table 1). However, such a scenario was reported by do Espírito Santo et al. (2010) about probiotic yoghurts fermented with açai pulp for detecting their prebiotic effects. Likewise, according to a study of do Espírito Santo et al. (2012) who assessed effect of the passion fruit peel powder on probiotic bacteria, this behavior collaborated with their findings. ...
The aim of this study was to investigate the effect of immature wheat grain (IWG) on the survival of Lactobacillus acidophilus NCFM (LNCFM), Lactobacillus casei 431 (L431) and Lactobacillus acidophilus 20079 (L20079) in yoghurts under cold storage. Furthermore, the impact of IWG on physicochemical, textural and antioxidative properties of yoghurts was evaluated. Fortification of yoghurt with IWG positively affected LNCFM and L20079 counts during cold storage whereas no statistical improvement was observed in the viability of L431. The addition of IWG clearly supported the antioxidative activity and total phenolic content in yoghurt. No statistical differences were discovered regarding syneresis and water holding capacity in all probiotic applications. Although, enrichment with IWG enhanced the firmness of probiotic yoghurts, it simultaneously reduced the cohesiveness and viscosity index. This study demonstrated that IWG may be used as a food additive for enhancing probiotic LNCFM and L20079 survival and providing functional aspects in yoghurt.
... The freeze-dried starter kefir culture kefir type B-heterofermentative culture-without production of CO 2 containing Lactobacillus plantarum, Lactobacillus rhamnosus, Lactoccocus lactis subspecies lactis and cremosis and Leuconostoc cremosis (Abiasa Inc., Saint Hyacinthe, Quebec, Canada) was used in this study. The culture was diluted in pasteurized, homogenized (3.25% fat) milk purchased locally from a commercial source (Ottawa, ON, Canada), stirred at 85 C for 15 min, portioned into sterile conical tubes (50 ml), and cooled to 42 C (Espírito Santo et al., 2010). Seven treatments were prepared containing three faba bean (whole, cotyledon and hull), and chickpea flours (1.5 g; 3%, w/v), chickpea mucilage, inulin (10 ml added to 40 ml milk) and the control without any additives. ...
... pH, TTA, bacterial enumerations were monitored once a week for a total of 4 weeks (1, 7, 14, 21, and 28 days) in triplicate for each batch at different dilutions (four serial dilutions of 1/10). From each dilution, a 100 ml aliquot was plated on MRS agar (Sigma-Aldrich Canada Ltd., Oakville, ON, Canada) as described previously (Espírito Santo et al., 2010), incubated (37 C, 24 h), and colony counts converted to log cfu/ml. ...
Changes in kefir storage (4 °C, 28 days) were evaluated every week in response to pulse (whole faba bean [Vicia faba L. minor] and its dehulled fractions – hulls and cotyledon; whole chickpea [Cicer arietinum L.)] and its crude mucilage) supplementation. Each supplement offered different profile of microbial count that was optimal at 14 days refrigerated storage. Bacterial growth was insignificant for faba bean hull (8.26–8.45 UFC/ml) and cotyledon (8.54–8.51UFC/ml) supplemented kefirs between 7 and 21 days storage. Titratable acidity (TTA) of kefirs decreased for the first week then increased with storage time at different rates for each supplement. Kefir pH decreased linearly with storage time differing significantly among samples after 14 days storage. Inulin and other supplementations improved lactate production and increased proteolytic activity with fermentation time. Antioxidant activity of kefir depended solely on the phenolic content and antioxidant activity of the supplements independent of storage time. The high antioxidant activity of the faba bean hull (13.03 μmol trolox eq/g kefir) supplemented kefir probably reflects its high phenolic content (57.53 mg gallic acid/g sample). Moreover, pulse supplements were superior to commercial inulin in maintaining kefir stability during refrigerated storage.
... Furthermore, the total CLA content of yogurts fermented with a yogurt starter culture (S. thermophilus and L. delbrueckii ssp. bulgaricus) and strains of Lb. acidophilus L10, Lb. acidophilus La-5, B. lactis Bb-12, B. lactis BL04, B94, B. lactis HN019 or B. longum BL05 was enhanced (from 20.5 to 66 %) by the addition of fructooligosaccharide, açai pulp and passion fruit by-product to the starting milk [97,107,108]. Likewise, addition of lactulose powder to the starting milk raised the cis-9, trans-11 CLA content of Kefir (by 39.6 %) when CLA-producing strains (L. ...
Conjugated linoleic acid (CLA) is a general term for all the geometric and positional isomers of linoleic acid. The cis-9, trans-11 CLA and trans-10 cis-12 CLA are considered to be the most abundant and essential isomers associated with health benefits. Though milk and dairy products are considered to be the major sources of CLA, the CLA content found in regular milk and dairy products is relatively low for effective health benefits in human beings. Thus, for effective health benefits, increasing the concentration of CLA in milk and dairy products is beneficial. Dietary supplementation with PUFA-rich lipid sources such as oilseeds and/or vegetable oils, fish meal, fish oil and microalgae and grass-based feeding can enhance the content of CLA in milk and dairy products. Application of CLA-producing bacterial strains during the fermentation process and ripening/storage are considered as potential strategies for enhancing the CLA content of fermented dairy products. Alternatively, the CLA content of milk and dairy products can be improved using genetic factor. In this paper, the latest scientific studies regarding CLA enrichment in milk and dairy products are reviewed, giving an overview of the effectiveness of the different CLA enrichment strategies and their combinations.
... S. thermophilus counts in samples of RB-added yoghurt gradually declined between days 1 and 14 of storage. Our findings are consistent with those of Espírito Santo, et al. [67], who discovered a comparable decline in S. thermophilus counts in açai yoghurts co-fermented with B. lactis B104 between 1 and 14 days. The findings agreed with those of Saccaro, et al. [68] and Senaka Ranadheera, et al. [69], who noted a small decline in S. thermophilus during the storage of probiotic yoghurts with fruit juice and L. acidophilus LA5. ...
... Many factors can influence the differential growth of different types of LAB in the presence of acai powder, including, e.g., change in redox potential, proteolytic activity of bacteria and release of low molecular weight peptides into the environment, or content of organic acids. According to Santo et al. [56] the addition of acai pulp to milk favored an increase in Lactobacillus acidophilus, Bifidobacterium animalis subsp. lactis and Bifidobacterium longum counts at the end of four weeks of cold storage. ...
In this study, the effects of the fermentation kinetics, determination of the number of lactic acid bacteria, texture, water holding capacity, and color of fermented soy beverages with acai powder (3 and 6% w/v) were investigated. The addition of acai powder significantly influenced the fermentation kinetics based on changes in pH, accelerating fermentation in the initial period. The results showed that the acai additive did not affect the enumeration of Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis. The presence of acai inhibited the proliferation of Streptococcus thermophilus compared to the soy beverage without acai powder added. However, the higher the acai additive, the more Streptococcus thermophilus bacteria were detected: 4.39 CFU/g for 6% acai powder sample and 3.40 CFU/g for 3% acai powder sample. The addition of acai to the soy beverage reduced its firmness, consistency, cohesiveness, and viscosity index after fermentation. A slight difference was observed in the lightness and whiteness of fermented soy beverages with 3% and 6% acai powder.
... In addition, açai has attracted the attention of the food and pharmaceutical market in recent decades, for presenting several bioactive properties, such as antioxidants, analgesics, neuroprotective and anti-inflammatory effects (Costa et al., 2018;Borges et al., 2021;Barbosa & Carvalho Junior, 2022). In the research by Santo et al. (2010) açai pulp was added to milk used in yogurt production to assess the fatty acid profile and viability of probiotic bacteria. The authors observed that the açai yoghurts had a higher content of polyunsaturated fatty acids, and that the addition of açai favored the increase in Lactobacillus acidophilus, Bifidobacterium animalis subsp. ...
The search for the development of new dairy products has been growing in recent years. Petit Suisse is a cheese that has been standing out in Brazil, reaching expansion in the market. The cheese added by fruits, such as açai (Euterpe oleracea Mart.), enhances the energy and nutritional value of the product. Its texture is an important feature, influencing the acquisition by the public. Thus, the objective was to develop and analyze the texture and physicochemical parameters of Petit Suisse cheeses added with açai. Three formulations (F1, F2 and F3) were prepared with different thickeners (xanthan gum and gelatin) and analyzed for texture, moisture, protein and pH parameters. The results indicated similarity between the different formulations for the texture parameters: F1 and F3 showed no significant difference (p ≥ 0.05), and F2 differed from F3 only in elasticity and cohesiveness. It was concluded that the application of different thickeners in Petit Suisse influenced its quality, being considered the best formulation that contained the mixture of thickeners (F3).
... In another study, viability of probiotic L. plantarum ATCC 14917 cells in Cornelian cherry juice decreased about 4 folds after 28 days of cold storage [26], while acai pulp ameliorated the viability of L. acidophilus, B. animalis ssp. lactis and B. longum throughout 4 weeks of cold storage [56]. Nevertheless, most of the probiotic strains applied for lactic acid fermentation of fruit juice seem at least to preserve their viability to the least limit (6 log cfu/mL) and they can deliver probiotic properties to the final product [57,58]. ...
Lactic acid fermentation of fresh fruit juices is a low-cost and sustainable process, that aims to preserve and even enhance the organoleptic and nutritional features of the raw matrices and extend their shelf life. Selected Lactic Acid Bacteria (LAB) were evaluated in the fermentation of various fruit juices, leading in some cases to fruit beverages, with enhanced nutritional and sensorial characteristics. Among LAB, Lactiplantibacillus (Lpb.) plantarum subsp. plantarum strains are quite interesting, regarding their application in the fermentation of a broad range of plant-derived substrates, such as vegetables and fruit juices, since they have genome plasticity and high versatility and flexibility. L. plantarum exhibits a remarkable portfolio of enzymes that make it very important and multi-functional in fruit juice fermentations. Therefore, L. plantarum has the potential for the production of various bioactive compounds, which enhance the nutritional value and the shelf life of the final product. In addition, L. plantarum can positively modify the flavor of fruit juices, leading to higher content of desirable volatile compounds. All these features are sought in the frame of this review, aiming at the potential and challenges of L. plantarum applications in the fermentation of fruit juices.
... relate the impact of civilization-induced diseases to insufficient dietary fibers ingestion from fruits and vegetables (Nawirska & Kwaśniewska, 2005). Also, the beneficial effects on probiotics viability exerted by some ingredients such as fruits and vegetables pieces or pulp to dairy products have been examined (Espírito Santo et al., 2010;Kourkoutas et al., 2006;Sendra et al., 2008). Do Espírito Santo et al., (2012) investigated the effect of the supplementation of total dietary fiber from apple, banana, or passion fruit by-products on the acidity, bacteria counts, and fatty acid profiles in skim milk yogurts co-fermented by four different probiotics strains. ...
Due to the high utilization rate of dairy products, enrichment of these products will successfully decrease or prevent diseases related with nutrition deficiencies. Fruits and vegetables in different forms (i.e., fresh, juices, powder, puree, and extract) are excellent sources for the enrichment of dairy products because of their desired taste, color, aroma, fibers, and vitamins content. So, this manuscript reviews the effect of some fruits and vegetables on the rheological behavior, physicochemical attributes, color parameters, sensorial and quality properties of dairy products including cheeses, ice creams, and yogurts. The physicochemical, color, texture, and sensorial properties of dairy products were affected with addition of fruits or vegetables. Also, the addition of these products contributes to the higher content of vitamins, natural colorants, minerals, polyphenols, crude fiber, and carotenoids. In addition, some fruits and vegetables are considered as potential dairy products stabilizing agent due to their desirable functional properties, such as water binding and holding, gelling and thickening ability. In summary, enrichment of cheeses, ice creams, and yogurts with fruits and vegetables increase the market share of these products due to the high demand for goods for an improved diet, rich in compounds with antioxidant activity and biological properties. This manuscript reviews the effect of some fruits and vegetables on the rheological behavior, physicochemical attributes, color parameters, sensorial and quality properties of dairy products including cheeses, ice creams, and yogurts.
... Carotenoids comprise the biggest group of pigmented compounds in nature, with approximately 600 isolated and changed with a decrease of MUFA and PUFA, as well as an increase of SFA and 60% of CLA, highlighting the potential of this functional property. The addition of açai pulp in yogurts was performed by Espírito Santo et al. (2010), who evaluated the effects of the fruit in probiotic bacteria development (Lactobacillus acidophilus, Bifidobacterium animalis ssp. lactis BI04 and Bifidobacterium longum BI05) and in the fatty acid profile (Table 1). ...
Abstract Fermented milks, with diverse manufacturing, fermentations and specific strains, have been consumed around the world, with a millennial knowledge of their production. These dairy products have a potential nutritional value, taking food industries to invest, nowadays, in dairy products with a functional and healthy appeal due to the changes in the habits and diet of the population. The addition of natural ingredients from vegetables and fruits into fermented milks is a tendency nowadays. The inclusion of natural additives may change the texture, composition, sensory attributes and increase of the shelf life since some compounds are related to have a high antioxidant activity, which decreases the development of deteriorating microorganisms. These called bioactive compounds are synthesized by plants and also may contribute to the fermented milk formulation, in special from fruits, which increase the sensory acceptance. Several classes of fruits bioactive compounds are associated to several health benefits and are a base of many studies about functional fermented milks, reported in this review. This theory background becomes essential for future studies and dairy products development.
... Sources of bioactive compounds, as fruits extract, pulps and juices, are usually studied as a functional additive in fermented milks, becoming an important source for dairy research and a tendency to industries Casarotti et al., 2018). The addition of fruits bioactive compounds in dairy formulations also enhance the viability and the development of probiotic cells, with a potential prebiotic property (Abdollahzadeh et al., 2018;Balthazar et al., 2019;Casarotti et al., 2018;de Campo et al., 2019;Espírito Santo et al., 2010;Vicenssuto & de Castro, 2020). ...
In fermented milks inoculated with two thermophilic strains (Lactobacillus bulgaricus and Streptococcus thermophilus), guabiroba pulp (Campomanesia xanthocarpa O. Berg) was added in different concentrations: 5% (I5 sample) and 10% (I10 sample), compared to a control sample, with no pulp addition. In these fermented milks, Bifidobacterium BB-12 was added and the samples were submitted to a progressive gastrointestinal simulation in vitro. The cells count was performed, including the survival rates for all the progressive steps of the simulated digestion. Total phenolic content (TPC) and antioxidant activity analysis by FRAP (Ferric Reducing Antioxidant Power) and DPPH (2,2-diphenyl-1-picrylhydrazyl) were performed in all the gastrointestinal steps. Before and during the entire gastrointestinal tract, the Bifidobacterium BB-12 count was 8 - 9 log CFU g⁻¹, above the recommended for a probiotic product, with a highlight in intestinal colon steps. The I10 sample showed the highest viable cell count, the highest total phenolic content and antioxidant activity throughout the entire gastric steps (p < 0.05). The fermented milk proved to be an effective matrix for the probiotic stability and incorporation of guabiroba components. Bioactive compounds present in the guabiroba pulp may have occasioned a prebiotic and protective effect on Bifidobacterium BB-12 after gastric conditions. The possible bioconversion of these compounds in more active forms can contribute to the absorption in epithelial cells, enhancing fermented milks with guabiroba pulp as important sources of dietary accessible bioactive compounds.
... This is because some strains of bacteria are able to change the fatty acid profile of milk during fermentation and produce functional fatty acids, including conjugated fatty acids, as the result of their growth and metabolism [135]. Moreover, the addition of other ingredients into the milk, such as prebiotics, can further increase the content of functional fatty acids in fermented milks [136]. In a study using Lactobacillus acidophilus and Bifidobacterium animals subsp. ...
The valorization of food wastes and byproducts has become a major subject of research to improve the sustainability of the food chain. This narrative review provides an overview of the current trends in the use of food byproducts in the development of dairy foods. We revised the latest data on food loss generation, the group of byproducts most used as ingredients in dairy product development, and their function within the food matrix. We also address the challenges associated with the sensory properties of the new products including ingredients obtained from byproducts, and consumers’ attitudes towards these sustainable novel dairy foods. Overall, 50 studies supported the tremendous potential of the application of food byproducts (mainly those from plant-origin) in dairy foods as ingredients. There are promising results for their utilization as food additives for technological purposes, and as sources of bioactive compounds to enhance the health-promoting properties of dairy products. However, food technologists, nutritionists and sensory scientists should work together to face the challenge of improving the palatability and consumer acceptance of these novel and sustainable dairy foods.
... The viability and/or in vitro assays of probiotic cultures are evaluated using conventional plating methods. 25,26 However, in the last few years, some authors have suggested probiotic quantification using quantitative real time PCR (qPCR) to avoid the underestimation of probiotic populations due to the difficulty in forming colonies after gastrointestinal in vitro assays, which can promote cellular damage to the bacteria. 5,27 Moreover, a prior treatment with propidium monoazide (PMA) was recommended by several studies [27][28][29] in order to allow the exclusion of the dead cells in qPCR analysis. ...
The viability and the in vitro gastrointestinal survival of Bifidobacterium animalis Bb-12 (Bifidobacterium Bb-12) in table spreads with different proportions of milkfat (MF) and palm olein (PO) (MF:PO 40:60 and MF:PO 20:80) were investigated for up to 28 days of storage at 5 °C. Moreover, the qPCR alone and combined with propidium monoazide (PMA) was compared with the traditional plate count method for determining the in vitro gastrointestinal survival of Bifidobacterium Bb-12 in table spreads after 35 days of storage. Formulations showed probiotic viabilities ranging from 8 to 9 log CFU/g during the whole period of storage, and the milkfat and palm olein in different concentrations did not affect this viability. Bifidobacterium Bb-12 showed good survival after six hours of the in vitro simulated gastrointestinal conditions during the storage period studied, with an average reduction of 1.70 (MF:PO 40:60) and of 2.16 log CFU/g (MF:PO 20:80). The results of qPCR with PMA treatment and the plate count method were similar and the qPCR without PMA treatment showed to overestimate the Bifidobacterium Bb-12 populations. However, spread MF:PO 40:60 showed Bifidobacterium Bb-12 population from 0.76 to 1.43 log CFU/g higher when compared to MF:PO 20:80. Thus, the results showed that table spreads, especially the food matrix with a higher proportion of milk fat, are suitable for the incorporation of Bifidobacterium Bb-12.
... Conventional dairy products are naturally low in n-3 LC-PUFA , and this has led to an interest in meeting our dietary requirements by altering the diets of dairy-producing animals, enriching dairy products directly. Many studies have enhanced the lipid composition of dairy products by adding bioactive compounds, oils, and fats from plant and marine sources in the production of yogurt (Espírito Santo et al., 2010;Georgakouli et al., 2016;Robertson et al., 2016). Table 3 presents studies that focus on the effects of dairy products enriched with PUFA on inflammatory markers in humans. ...
Dairy product consumption is often associated with negative effects because of its naturally high levels of saturated fatty acids. However, recent research has shown that dairy lipids possess putative bioactivity against chronic inflammation. Inflammation triggers the onset of several chronic diseases, including cardiovascular disease, type 2 diabetes mellitus, obesity, and cancer. This review discusses the anti-inflammatory properties of dairy lipids found in milk, yogurt, and cheese, and it examines them in relation to their implications for human health: their protective effects and their role in pathology. We also consider the effect of lipid profile alteration in dairy products—by using ruminant dietary strategies to enrich the milk, or by lipid fortification in the products. We critically review the in vivo, in vitro, ex vivo, and epidemiological studies associated with these dairy lipids and their role in various inflammatory conditions. Finally, we discuss some suggestions for future research in the study of bioactive lipids and dairy products, with reference to the novel field of metabolomics and epidemiological studies.
... This fruit is a rich source of polyphenols, being especially rich in anthocyanins, proanthocyanidins, and other flavonoids, well-studied for their antioxidant and anti-inflammatory potential. [16][17][18][19] Even though data related to the impact of tropi- cal fruit pulp on probiotic survival in food matrices are scarce, a study reported that the addition of açaí pulp promoted increased probiotic viability, 20 demonstrating that probiotic products with açaí pulp may be used as promising vehicles for these microorganisms. Açaí has turned into an important crop widely consumed in Brazil, and is one of the most popular fruits exported from the Amazon estuary. ...
The effect of açai pulp ice cream and of its supplementation with inulin (I), whey protein concentrate (WC), and/or whey protein isolate (WI) on the viability and resistance to simulated gastrointestinal stress of the probiotic Lactobacillus (Lb.) rhamnosus GG strain throughout storage at -18 °C for up to 112 days was evaluated and morphological changes during stress were monitored. Lb. rhamnosus GG viability was stable in all formulations for up to 112 days of storage, preserving populations around 9 log CFU g(-1). Compared to the fresh culture, Lb. rhamnosus GG showed higher survival under simulated gastrointestinal conditions when incorporated into açai ice cream, indicating that the presence of the food matrix contributed to the microorganism survival. A reduction of at least 5 log cycles of Lb. rhamnosus GG was observed in all formulations after the gastrointestinal simulation in all storage periods assessed. The addition of I, WC, and/or WI did not show any significant effect on the probiotic survival under simulated gastrointestinal stress (p < 0.05). Compared to the fresh culture, fewer morphological changes were observed when the probiotic was added to ice cream. Thus, the açai pulp ice cream was shown to be a suitable matrix for Lb. rhamnosus GG, improving its survival under in vitro simulated gastrointestinal conditions.
This research paper focuses on enrichment of yoghurt containing probiotic Lactobacillus casei with persimmon (Diospyros kaki) powder in concentrations of 0 (Control) and then 0.5, 1.0, 1.5 and 2.0% (A–D respectively) and determination of some characteristics of the product during refrigerated storage for 21 d. Powder addition affected the color characteristics, textural properties, titratable acidity and water-holding capacity values. The viability of both yoghurt bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) and L. casei increased proportionally to adding persimmon powder for all storage days. Furthermore, addition of fruit powder increased short-chain fatty acid and polyunsaturated fatty acid contents. According to sensory analysis results, sample D had the lowest scores from the panelists, whereas the Control together with samples B and C were the most liked yoghurts in terms of flavor characteristics. In terms of overall acceptability, all of the samples received scores over three points on a five-point scale throughout storage. This study indicates that persimmon powder enriched yoghurt is a good vehicle for L. casei and yoghurt bacteria with improved fatty acid profile and acceptable sensory characteristics.
The rapid growth of the world population has increased the demand for new food sources, constituting a major challenge concerning the maximum use of existing food resources. The fruits of Amazonian palm trees have excellent nutritional composition and bioactive compounds. This review highlights four fruits of Amazonian palm trees that are still little explored by the food industry: açai (Euterpe oleracea), pupunha (Bactris gasipaes), buriti (Mauritia flexuosa), and tucumã (Astrocaryum aculeatum). This paper aims to inspire new ideas for researching and developing products for the food industry. It also explores the impacts of Amazonian palm fruits on health, highlighting their role in disease prevention through their nutritional effects.
Bifidobacteria, frequently present in the human gastrointestinal tract, play a crucial role in preserving gut health and are mostly recognized as beneficial probiotic microorganisms. They are associated with fermenting complex carbohydrates, resulting in the production of short-chain fatty acids, bioactive peptides, exopolysaccharides, and vitamins, which provide energy and contribute to gut homeostasis. In light of these findings, research in food processing technologies has harnessed probiotic bacteria such as lactobacilli and bifidobacteria for the formulation of a wide range of fermented dairy products, ensuring their maximum survival and contributing to the development of distinctive quality characteristics and therapeutic benefits. Despite the increased interest in probiotic dairy products, introducing bifidobacteria into the dairy food chain has proved to be complicated. However, survival of Bifidobacterium species is conditioned by strain of bacteria used, metabolic interactions with lactic acid bacteria (LAB), fermentation parameters, and the temperature of storage and preservation of the dairy products. Furthermore, fortification of dairy foods and whey beverages with bifidobacteria have ability to change physicochemical and rheological properties beyond economic value of dairy products. In summary, this review underscores the significance of bifidobacteria as probiotics in diverse fermented dairy foods and accentuates their positive impact on human health. By enhancing our comprehension of the beneficial repercussions associated with the consumption of bifidobacteria-rich products, we aim to encourage individuals to embrace these probiotics as a means of promoting holistic health.
This review discusses the current technological approaches successfully used to fortify yogurts with polyunsaturated fatty acids (PUFA). The PUFA sources, inclusion strategies, effects of the fortification process on the yogurt’s properties, as well as the health benefits of the PUFA-fortified yogurts are systematically presented. The main PUFA sources explored have been fish, algal, and flaxseed oils, and walnut. Oils, seeds, nuts, vegetable flours, oil-in-water emulsions, and encapsulated emulsions may be added to obtain fortified yogurts. The effects of PUFA fortification depends on the technological approach used. Diet supplementation with PUFA-fortified yogurts reveals cardio-protective effects and cardiovascular disease risk reduction.
Yoghurt is a coagulated dairy product that is fermented by typical starter cultures. Yogurt has the highest demand rate among fermented products due to its sensory properties. Well‐consumed food products are being enriched by either adding nutrients or improving the already available content for the development of the product. From this point of view, protein enrichment is one of the approaches that contribute to the nutrient content of food products. The addition of plant‐based protein is a step that improves the nutrient content and is a sustainable approach for the functionalization of the product. In the present study, two types of plant protein were added; chickpea and pea in two different concentrations of 0.5% (w/w) and 1% (w/w) to determine the changes in the physicochemical, textural, microbiological, and sensory properties of the yoghurt during storage at 4°C for 21 days. In yoghurt samples, pH value, titratable acidity, colour measurements (L*, a*, b*), texture parameters (firmness, consistency, cohesiveness), microbiological contents show a significant difference during the storage period (p<0.05). On the other hand, adding plant protein had no significant difference in syneresis value during storage (p>0.05). The sensory evaluation results highlighted that protein enrichment develops consistency, mouthfeel, and oiliness scores compared to the control product (no plant protein added sample). These significant sensory modalities are determined by the casein network and water‐binding capability of the proteins, which was visible as a result of this study.
Conjugated linoleic acid (CLA), a group of 18 carbon conjugated dienoic acids, has been considered a promising food supplement owing to its various physiological benefits to human health. Owing to a high isomer selectivity of the product and a simple isolation and purification process, microbial CLA has become a research hotspot. Many food-grade bacteria such as Lactobacillus and Bifidobacterium have been reported to possess CLA-production ability. Particularly, Bifidobacterium has high bio-conversion rate and enhanced CLA production, and is one of the best and most promising CLA producers among microorganisms. Consequently, this article aimed to review the current knowledge about Bifidobacterium CLA producers, the complex factors regulating CLA production in Bifidobacterium, the role of CLA production in Bifidobacterium, and the potential mechanism underlying Bifidobacterium CLA production. In summary, the above information offers novel insights into the production of food-grade CLA as well as the rational design of health-promoting fermented foods or synbiotics.
Fermented milk products have received a lot of attention in recent years due to their nutritious effect and health benefits. One of the benefits offered by fermented milks is their potential as probiotic, prebiotic, and synbiotic food carrier. It is evident that fermented milk products such as yogurt and kefir can be successfully formulated with probiotics and prebiotics as the key ingredients to develop functional food products that promote health and wellness. Over the past century, research studies have been continuously established to strengthen the fundamental scientific knowledge and improve the technological aspects of fermented milk products. Particular attention has been given to the critical factors that influence the quality and acceptability of fermented milk products and aspects that link the nutritional value and health benefits with the presence of probiotics, prebiotics, and their combination (synbiotic). This chapter provides the necessary background and key details on characteristics, compositions, formulations, and potential health benefits of fermented milk products as the most popular vehicles for probiotics, prebiotics, and synbiotics mainly focusing on the two well-known products, yogurt and kefir.
The effect of passion fruit and buriti pulps on probiotic and starter lactic acid bacteria growth and on fermented milk (FM) was evaluated. Buriti pulp showed higher amounts of lipids, total phenolic compounds (PC), β-carotene, lycopene and antioxidant activity (AA) than passion fruit. However, passion fruit was used more efficiently as a carbon source by all strains. Lacticaseibacillus casei SJRP38 showed the best results in the presence of passion fruit (1.8 log CFU/mL increase compared to the initial population) and the lowest reduction in the presence of buriti, thus it was selected to produce FM. Acidified milk (AM) with the same fruit pulps was used as a control. The buriti pulp did not affect the kinetic parameters of FM compared to the control. However, the addition of fruit pulps increased the PC in both FM and AM, and FM resulted in a greater increase (33.4 to 141.6%) than AM (21.4% to 87.9%). Also, buriti pulp was able to increase (6 to 8%) the AA of the FM when compared to the AM. FM with buriti pulp stood out for its high amount of total PC, which indicates its high potential to be used as a functional food.
This study was performed to evaluate the effects of using native and commercial probiotic strains on biochemical, microbiological, and sensory properties of yogurt. The viability of probiotic bacteria in all samples exceeded 6 log CFU/ml required to provide health benefits. The native Iranian Lactobacillus casei showed the highest viability throughout storage (8.5 log CFU/ml at the end of storage). Three distinct phases were observed in pH, acidity, and redox potential during the fermentation of all samples. Commercial L. casei strain had the lowest mean acidity increase rates and the longest incubation times. The growth of Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus thermophilus in probiotic yogurt was improved compared to the control yogurt. The control sample had the lowest score in all sensory parameters evaluated. Overall, yogurt containing native Iranian L. casei strain is recommended because of its good sensory and microbial properties. Among different functional food products, probiotic dairy products are of great interest and yogurt is the most popular probiotic carrier. In most cases, commercial strains of Lactobacillus and bifidobacteria are incorporated into yogurt and native strains have not been studied widely. In this regard, isolation, characterization, and investigation of the effect of their application in dairy products can be promising in the development of functional dairy products with acceptable qualitative characteristics.
Kefir tarihi yüzyıllar öncesine dayanan Kafkas dağları, Tibet ve Moğolistan kökenli fermente bir süt ürünüdür. Bazı bakteriler gelişim ve metabolizmalarının sonucu olarak süt ürünlerinde fermantasyon boyunca farklı yağ asidi profilleri ve fonksiyonel yağ asitleri oluşturabilirler. Çalışmada kefir üretimleri inek sütüne %1, %2 ve %3 oranlarında maltodekstrin ve inülin eklendikten sonra gerçekleştirilmiştir. Kontrol olarak maltodekstrin ve inülin eklenmemiş sütten kefir üretilmiştir. Kefir üretiminden önce çiğ sütte genel kimyasal bileşim (kurumadde, yağ, protein ve kül analizi) ve konjüge linoleik asit (KLA) analizi gerçekleştirilmiştir. Kefirlerde depolamanın 0, 2, 7, 14 ve 21. günlerinde KLA analizleri yapılmıştır. Bu çalışmanın sonuçları fermantasyon işlemi ile KLA miktarının arttığını fakat maltodekstrin ve inülin ilavesinin depolama boyunca KLA miktarı üzerine bir etkisinin olmadığını göstermiştir.
The main constituents of the Euterpe oleracea Mart., Arecaceae, fruits (açaí) are anthocyanins. This paper aimed to standardize the extraction process and characterize an anthocyanin-rich dry extract obtained from this fruit. A 23 full factorial design was used. The volumes of ethanol 92% and acetic acid and the extraction time were used as factors. Total solids and anthocyanins content were used as feedback. The dry extract was obtained by freeze-drying. The content of anthocyanins was determined spectrophotometrically. Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimeter, Thermogravimetry, Scanning Electron Microscopy, and Atomic Absorption Spectrometry were used for characterizingthe dry extract. The DPPH method was used for evaluating radical scavenging activity. The extraction conditions were established. The most influent factor was the volume of acetic acid. The dry extract moisture content was equal to 1.39 ± 0.25%, the evaporation residue 97.25 ± 1.28%, total ashes 0.62 ± 0.12%, and the anthocyanin content was 61.75 ± 3.28%. The elemental composition shows the presence of manganese 4.85 ppm, iron 1.62 ppm, zinc 0.05, copper 1.38 ppm, calcium 1.01 ppm, cadmium 0.003 ppm, nickel 0.37 ppm, and lead 0.38 ppm. The dried extract IC50 estimated by the radical scavenging assay with DPPH was 31.25 ± 2.31 ppm. The optimal extraction conditions were: the volume of ethanol 92%: 400 ml; volume of acetic acid: 75 ml; an extraction time: 4 h. Keywords: Açai, Anthocyanins, Antioxidant, Dry extract, Extraction, Factorial design
Background. The aim of this study was to develop nutritious fermented milk products from camel's milk fortified with kiwi fruit and avocado puree, and fermented using probiotic strains. Material and methods. Stirred yoghurt made from camel's milk, supplemented with avocado and kiwi fruit puree as natural additives at different levels (2, 4 and 6%) and fermented with a mixture of yoghurt culture and probiotic Lb. acidophilus and B. lactis. The stirred yoghurt was chemically analyzed, and the microbial count, antioxidant activity and total phenolic content were determined. The stirred yoghurt from different treatments was assessed for viscosity and sensory properties. Results. The highest viable counts of Lb. acidophilus and B. lactis were enumerated in yoghurts fortified with 6% avocado, whereas the control had significantly lower counts. The radical scavenging activity (RSA) and the total phenol content (TPC) decreased for the control of the stirred camel's milk yoghurt after 21 days of storage, whereas the samples fortified with kiwi or avocado puree retained high RSA and TPC content throughout the storage period compared to the control. Conclusion. Addition of 4% avocado or 6% kiwi pastes to fermented camel's milk produces a higher quality and acceptability of camel's milk.
Background:
The aim of this study was to develop nutritious fermented milk products from camel’s milk fortified with kiwi fruit and avocado puree, and fermented using probiotic strains.
Methods:
Stirred yoghurt made from camel’s milk, supplemented with avocado and kiwi fruit puree as natural additives at different levels (2, 4 and 6%) and fermented with a mixture of yoghurt culture and probiotic Lb. acidophilus and B. lactis. The stirred yoghurt was chemically analyzed, and the microbial count, antioxidant activity and total phenolic content were determined. The stirred yoghurt from different treatments was assessed for viscosity and sensory properties.
Results:
The highest viable counts of Lb. acidophilus and B. lactis were enumerated in yoghurts fortified with 6% avocado, whereas the control had significantly lower counts. The radical scavenging activity (RSA) and the total phenol content (TPC) decreased for the control of the stirred camel’s milk yoghurt after 21 days of storage, whereas the samples fortified with kiwi or avocado puree retained high RSA and TPC content throughout the storage period compared to the control.
Conclusions:
Addition of 4% avocado or 6% kiwi pastes to fermented camel’s milk produces a higher quality and acceptability of camel’s milk.
La fibra dietética ayuda a reducir el riesgo de padecer algunas enfermedades crónicas, a pesar de esto, su ingesta mundial es menor que los niveles recomendados. Este hecho motiva a la industria alimentaria a incorporar fibra dietética, obtenida de fuentes vegetales en productos alimenticios, como el yogurt. El presente estudio tuvo como objetivo evaluar las principales características de calidad de diferentes formulaciones de yogurt, en función de la incorporación de epicarpio de maracuyá deshidratado (EMD), con alto contenido de fibra dietaria (71,4 ± 0,04%), en concentración de 0 y 0,5% y el efecto que ejerce la grasa láctea presente en la leche cruda de vaca, en concentración de 0, 0,5 y 3,0%. Algunas propiedades fisicoquímicas, tales como pH, acidez titulable (%), viscosidad (cP) y parámetros de color por método CIELab fueron evaluadas en seis formulaciones diferentes. De acuerdo con los resultados obtenidos, se realizó un análisis sensorial y se evaluó la estabilidad de dos formulaciones de yogurt, durante un periodo de almacenamiento de 29 días, a 4°C. La incorporación de EMD contribuyó significativamente al incremento de acidez y la viscosidad en el producto. El EMD favoreció la estabilidad del gel y permitió obtener resultados aceptables en atributos sensoriales hasta el día 15 de almacenamiento. La incorporación de EMD en la elaboración de yogurt permitió enriquecer el valor, debido al aporte de fibra dietaria, la cual, puede actuar como sustituto funcional de la grasa láctea.
Amazonian plants possess high amounts of little-explored lipid compounds. Chemical parameters and lipophilic compounds present in twelve oils and fats from different Amazonian plants were characterized. The fatty acids identified reveal saturated fats, such as babassu oil and muru-muru fat (rich in lauric acid), ucuhuba fat (myristic acid), and bacuri fat (palmitic acid). Buriti, pracaxi, and patawa oils showed high oleic acid content. Passion fruit seed and Brazil nut oils had high levels of the polyunsaturated fatty acids rich in linoleic acid. The oleaginous plants had high unsaturation degree and high content of medium-length-chain fatty acids due to high values of iodine, saponification, and peroxide. For methyl tocols and total carotenes, a simultaneous determination method was used and revealed high levels of these vitamins in buriti oil. No previous work in the literature has described all these parameters in Amazonian oils and fats, especially regarding plant species such as bacuri, cupuassu, and ucuhuba. These results provide information on oils and fats that could be used as alternative sources of raw material for the food and pharmaceutics industries.
The aim of this study was to evaluate the effect of hydrolysate collagen (HC), cheese whey (CW), and açaí pulp (AP) content on the characteristics of probiotic dairy beverages. Higher levels of CW and AP decreased beverage ash and protein content, and increased lipid and carbohydrate content and energy values. HC and AP positively affected the viscosity of the formulations, which exhibited pseudoplastic behavior. In terms of quality parameters, higher levels of CW and AP increased both the syneresis (2.56–5.74%) and sedimentation index values (1.80–1.87%) of the formulations. The beverages presented adequate stability of physicochemical and microbiological parameters during 28 days storage. Formulations containing average levels of CW (22.5%), AP (30%), and HC (1.0%) achieved the best results regarding sensory analysis, with acceptability index values above 70% for most parameters.
Practical applications
Demand for probiotic foods is currently increasing due to their potential health benefits. Although the utilization of cheese whey in dairy beverage development is a challenge to the food industry because of the viscosity of the final product, this situation can be improved via the use of selected ingredients. Açaí pulp, hydrolyzed collagen, and cheese whey, when used in the production of probiotic dairy beverages, offer to the market a new functional product of adequate quality and acceptability.
The effect of date extract (DE) addition on the microbiological, physicochemical, rheological, and sensory characteristics of probiotic fermented milk was investigated. DE was added to milk at the level of 0–12 g/100 mL; the mixtures were then fermented with Lactobacillus acidophilus La-5. The initial probiotic concentrations ranged between 8.16 and 8.77 log10 CFU/g. Although the highest DE concentration led to a significant count reduction (from 8.16 to 6.44 log10 CFU/g), the probiotic concentration was above 6 log10 CFU/g in all samples during 14 days of storage at 4 °C. All treatments had similar ash, fat, and protein content. As the DE concentration increased, total solids (from 9.98 to 16.88 g/100 g) and ferric reducing antioxidant power (from 4.01 to 22.24 mg ascorbic acid equivalent/100 g) increased. Samples with higher DE concentration showed lower pH and syneresis, and higher acidity. DE addition could slightly increase the viscosity from 53.48 to 69.95 mPa s. According to power law model, shear-thinning behavior was observed at all concentrations. DE-added products had lower L* and higher a* color values. Fortification with DE did not adversely affect the sensory acceptability. The date extract, therefore, seems to be a suitable candidate to improve the nutritional quality of probiotic dairy foods.
The aim of the study was to evaluate the biocompounds content and physical characteristics of açaí pulp dried by different methods in order to determine the most suitable drying method. The açaí pulp with a high content of lipids (53.31 g/100 g) was dried using spouted bed, freeze dryer and spray dryer. The samples were evaluated for anthocyanins, carotenoids and moisture content, and also for color and microstructure parameters. All samples showed moisture content less than 5 g/100 g. Powders obtained by freeze dryer and spouted bed showed lower color difference than fresh pulp. Microstructure analysis exhibited particles with irregular surfaces and diameters less than 100 μm. The açaí pulp dried by freeze drying presented the best results under the conditions and methods evaluated, once it resulted in a product with higher contents of anthocyanins (5.87 ± 0.53 mg/g of dry matter) and carotenoids (38.28 ± 0.69 μg/g of dry matter), as well as lower moisture content (2.65 ± 0.11 g/100 g). Furthermore, no lipid oxidation occurred in the freeze-drying pulp. Therefore, we concluded that açaí pulp can be dried and still preserve high concentration of biocompounds, and also physical properties, being suitable to be applied in healthy foods.
RESUMO A adição, em iogurtes, de polpa de Juçara como fonte de compostos fenólicos pode modificar as características físico-químicas, contribuir para atividade antioxidante, e interferir na viabilidade de bactérias probióticas e na aceitação sensorial. Com o objetivo de verificar o efeito da adição de polpa de Juçara em iogurte, foi realizado um experimento, em delineamento inteiramente casualizado, em parcelas subdivididas. A parcela principal foi o teor de polpa, com seis níveis (0, 5, 10, 15, 20 e 25%) e, como subparcela, o tempo de armazenamento, a 5 oC, com cinco níveis (1, 7, 14, 21 e 28 dias). Os teores percentuais médios de gordura, cinzas, extrato seco total e acidez dos iogurtes não diferiram (P ≥ 0,05). O teor de proteína diminuiu com o aumento do teor de polpa, variando de 4,07% (F0) a 2,9% (F25%). O conteúdo fenólico total e a atividade antioxidante foram maiores no iogurte com 25% de polpa, atingindo valores de 117,84 mg de AGE/100g e 6,95 µmol Trolox/g, respectivamente, assim como a contagem de bactérias probióticas, que variou de 3,17 log UFC.g-1 (F0) a 6,34 log UFC.g-1 (F25%), nos iogurtes, após 28 dias de armazenamento. A adição da polpa de Juçara favoreceu a multiplicação e a viabilidade de bactérias probióticas, contribuiu para o aumento do conteúdo fenólico total e para maior atividade antioxidante dos iogurtes, que apresentaram boa aceitação sensorial pelo consumidor.
Dairy products have been widely used for adding various biomolecules with the aim of improving their functional properties and health benefits. In this study, the physicochemical properties and sensory acceptance of yogurts enriched with sacha inchi (Plukenetia volubilis) seeds (SIS) and β-glucans from Ganoderma lucidum (BGGL) were investigated. The angiotensin-converting enzyme-inhibitory activity of some yogurt samples was also evaluated. Yogurts were produced from reconstituted skim milk powder, and SIS (4% wt/wt) and BGGL were added at different concentrations (0-1.5% wt/wt). The fermentation kinetics were not affected by the enrichment process. The addition of SIS and BGGL significantly increased (P < 0.05) the contents of protein, fat, carbohydrates, ash, total solids, aspartic acid, serine, arginine, glycine, threonine, tyrosine, and alanine. α-Linolenic (49.3%) and linoleic (32.2%) acids were the main fatty acids found in the enriched samples, whose values were about 50- and 25-fold higher than those of the control yogurt. The textural parameters (firmness, consistency, cohesiveness, and index of viscosity) of the enriched yogurts were significantly lower (P < 0.05) than those of the control samples during the whole storage period. All enriched yogurts showed a sensorial acceptance higher than 70% by untrained panelists. The angiotensin-converting enzyme-inhibitory activity of some selected yogurt samples ranged between 36 and 59%. These results indicate that SIS and BGGL could be used as natural ingredients for improving the nutritional value of yogurt and fermented milks.
Experimental yoghurts were made with 13% reconstituted skim milk supplemented with 1, 2, 3% rice bran (RB) and inoculated with probiotic culture of Lactobacillus casei 431. The products were stored at 4 °C for 3 weeks. During this period, the viability of the probiotic L. casei 431 strain and yoghurt starter cultures were evaluated. In addition to this, some physicochemical, antioxidative and sensory properties of yoghurts were also determined. L. casei 431 remained above the 8 log CFU/g throughout the storage period in yoghurts fortified with 2% and 3% RB. Addition of rice bran decreased the syneresis and viscosity values whereas it increased scavenging activities of DPPH radical. However, yoghurts with RB had less sensory scores compared to plain yoghurt.
Conjugated derivatives of fatty acids, namely conjugated linoleic acid (CLA) and conjugated α-linolenic acid (CLNA), have attracted much attention of the scientific community over the last two decades due to their biological properties. In fact, several studies realized in animal models and/or cell cultures have shown anticarcinogenic, antiobesity, antiatherogenic, antidiabetic, and immunomodulatory activities. CLA and CLNA isomers are commonly present in ruminant’s derived foods mainly because of the action of microorganisms on linoleic acid (LA) and α-linolenic acid (LNA), respectively. However, the natural concentrations of CLA and CLNA found in these food products do not seem to be sufficient to have any significant therapeutic effect and thus there are efforts to obtain CLA- and/or CLNA-enriched foods. Several food-grade microorganisms, such as bifidobacteria, lactic acid bacteria (LAB), and propionibacteria, are capable of producing CLA and CLNA from LA and LNA, respectively, given their linoleate isomerase activity. These microorganisms could thus be used to produce CLA-enriched foods either as starter or adjunct cultures or as biocatalysts producing CLA and/or CLNA that can be used as natural food additives. This chapter presents a comprehensive outlook of the biotechnological production of CLA and CLNA and a discussion of its technical issues, limitations, challenges, and potential food and nutraceutical applications based on nutritional value and biological properties.
This study investigated the effects of various concentrations (0, 0.1, 0.2 and 0.4%, v/w) of olive leaf extract on low fat apricot yogurt. The addition of the olive leaf extract during the preparation of low fat apricot yogurt significantly (P < 0.05) influenced dry matter, protein and ash contents and pH value. Streptococcus thermophilus count was statistically (P < 0.05) affected by addition of the olive leaf extract. The water holding capacity values of the samples decreased throughout the storage period. The viscosity values of the samples with olive leaf extract were not significantly (P > 0.05) different from the control samples (except 15th day). Yogurt including 0.4% olive leaf extract had the highest antioxidant activity at the end of the storage.
Practical Applications
Olive and olive leaf extract have numerous benefits such as antioxidant, antimicrobial and hypocholesterolemic properties. This study has proved the effect of the olive leaf extract on the chemical, microbiological, antioxidant and sensory properties of yogurt. The effect of the olive leaf extract on the viability of Streptococcus thermophilus was found to be very important. A functional product with high antioxidant properties can be produced by adding olive leaf extract during yogurt production.
Abstract
It was aimed to i) investigate if seabuckthorn whole fruit (S), and seabuckthorn purified mucilage (SP) addition into yogurt enhance bacterial viability, by measuring total bacterial counts of different yogurt trials on selective media, pH and total titratable acidity (TTA) during 28 day cold storage at 4 °C, as well as ii) measure antioxidant activities of microwave extracted seabuckthorn crude mucilage (SC) and SP using oxygen radical absorbance capacity (ORAC) and DPPH scavenging activity. After 21 days of cold storage, yogurts with S and SP maintained higher viable bacteria counts in both of probiotics, Lactobacillus acidophilus (9.3 log cfu/mL) and Bifidobacterium lactis (9.2 log cfu/mL), higher TTA (0.8%), and lower pH (5.0) compared to the controls (P < 0.05). SC exhibited strong antioxidant activity with an ORAC value of 138.9 μmol Trolox equivalents/100 g, and a %DPPH scavenging activity value of 37.0%. Results of this study suggest S may serve as a new prebiotic source for functional foods and nutraceutical applications.
Keywords
Microwave-extraction; Probiotic; Seabuckthorn; Selective media
This chapter provides a short introduction to the chemistry and biosynthesis of conjugated linoleic acid (CLA) and discusses the possible methods by which the CLA content of fermented food products can be increased. One possible way to produce foods with enhanced levels of CLA is the application of CLA-enriched raw materials. Therefore, the CLA content of raw materials and factors that influence their CLA content are discussed first. CLA formation during the processing of fermented milk and meat products is explored and functional foods are also discussed. The chapter also includes a section on the health effects of CLA.
Probiotic foods products are a fast growing area of functional food, as found to be strongly accepted by the consumers. The application of probiotics in dairy products is already common. However, the food industry is seeking to produce different varieties of probiotic foods other than dairy products with potential health benefits. The success of new probiotic foods depends on the ability of probiotics to provide sufficient numbers of viable cells that beneficially modify the gut microflora of the host. It is highly desirable that the viable counts of probiotics in the final product to be at least 106–107 cfu ml−1 to offering health benefits to the consumers. Therefore, the objective of this study is to review the applications of selected probiotics in dairy and non-dairy foods and their viability during the storage.
Asaí is a neotropical palm with fruits that are traditionally consumed by native communities in the Amazon. Consumption has increased due to the antioxidant contents. Distribution of this wild Amazonic palm is widespread and it is possible to find more than one species. While in Brazilian forests, E. oleraceae is the most abundant; in the eastern Amazon, the principal species is E. precatoria. During recent decades, many institutes, universities and research centers have studied many topics related to the palm. Despite these advances, harvest indices, postharvest handling, as well as processing lack the necessary knowledge for the well-timed harvest of bunches and fruit handling, in order to take advantage of this biological resource. Skin color and pigment contents are good harvest indices. Fresh fruits are not usually consumed but pulp, beverages and dehydrated powders constitute commercial products. To obtain good products from the fruit, postharvest handling includes conditioning operations such as selection and classification, which assure the delay of fruit decay and fermentation. Some processing protocols have been developed in order to obtain pulp and dry powder from asaí fruit, which preserve high antioxidant activities due to polyphenolic compounds. Uses of fruit pulp and dehydrated powders have diverse applications and all of them preserve a functional condition, such as in energy bars, instant beverages, chocolate fillers and gummy confectionery. Asaí fruits exhibit interesting options for the food industry with high potential for inclusion in many derivatives that satisfy industrial requirements, which could be reinforced with advances in technology and innovative processing to enhance preservation of the functional bioactive compounds.
Three M17 agar media for the enumeration of Streptococcus thermophilus in fermented dairy products, such as yogurt and other commercial fermented milk, were compared: CM785 Oxoid®, 15108 Merck®, and a M17 made in the laboratory. In all cases, the highest counts were taken on Oxoid® medium. The difference between the averages of the counts on the Oxoid® M17 and the laboratory-made M17 is significant, (P ≤ 0.05). However, the difference between the counts on the Oxoid® and Merck® media is not significant.
Brazil is the biggest producer, consumer and exporter of açaí drink, made from the açaí palm's fruit. This drink or açaí pulp is usually commercialized under room temperature or in a frozen way resulting in important nutritional losses. This study aimed to evaluate some nutrients from the lyophilized açaí pulp. Humidity, total solids, ash and total lipids values were analyzed using the AOAC method. Carbohydrates including fibers were calculated by difference and the total nitrogen values were investigated by AACC method. Mineral concentration was analyzed in a mass spectrophotometer and fats by methyl esters preparation identified in a gas chromatography. Results from analytical determinations showed that the powder product is a very caloric food, 489.39 Kcal/ 100 g lyophilized pulp, specially due to the high lipid contents (40.75%), from which 52.70% are represented by oleic acid (C18:1) and 25.56% by the palmitic (C16:0). Total carbohydrate content was 42.53% ± 3.56 and the protein's was 8.13 g ± 0.63/100 g. Mineral profile evaluation demonstrated that the potassium (900 mg/100 g lyophilized açaí) and the calcium (330 mg/100 g lyophilized açaí) were the minerals observed in abundance. Magnesium has also shown important concentrations (124.4 mg/100 g lyophilized açaí), different from the iron (4.5 mg/100 g lyophilized açaí). Based on the results obtained on the nutritional composition evaluation of the lyophilized açaí pulp, it is possible to conclude that this process can be considered as an excellent alternative for preserving this pulp due to the important nutritional compounds found in it.
Açaí (Euterpe oleracea Martius) is a typical palm tree from the Amazon, growing spontaneously in states of Pará, Amazonas, Amapá and Maranhão. It has been highlighted by the potential of its products, especially because of the economic importance for the regional fruit growing. The açaí fruits are very appreciated by their pulp flavour. In the açaí pulp, there is a significant amount of lipids, around 53%, in a dry basis, turning out to be an excellent source of essential fatty acids. The main purpose of the present work was to establish the fatty acid content in the lipid fraction of açaí pulp using high resolution gaseous chromatography. The açaí oil was obtained by enzymatic technology in water has been indicated as an alternative for vegetable oils extraction from pulp of fruits. A significant difference was not observed in the composition of the fatty acids present in açaí oil obtained from either process. In both cases, the oil is high in monounsaturated fatty acids (68% to 71%) and in polyunsaturated fatty acids (7.8% to 10.6%).
Analyze the social returns and technological progress in the açaí cultivation in the State of Pará. The açaí is the basic food for a great majority of the Pará's population, especially the people living by the river's side that explore the fruit in the extractive way. The açaí demand and supply relationships were estimated for the purpose of the obtaining the price-elasticity, estimating the social returns of the technological adoption with respect to the economy of the açaí cultivation in Pará. The results showed, that since 2002, the benefits with the technological adoption for the society have been growing to a medium rate of 36.64% and, in 2005, the estimated value of the total benefit was of the order of R$238 million.
In the present work, the combined effect of milk supplementation and culture composition on acidification, textural properties, and microbiological stability of fermented milks containing probiotic bacteria, was studied. Three powders (whey, casein hydrolysate, and milk proteins) were tested as supplementation. Two strains of probiotic bacteria, Lactobacillus acidophilus (LA5) and Lactobacillus rhamnosus (LC35), were used in pure culture, and in mixed culture with Streptococcus thermophilus (ST7). Acidifying activity was enhanced with mixed cultures, compared to pure cultures resulting in a shorter time to reach pH 4.5. Acidifying activity was greatly improved with casein hydrolysate, with a reduction of the fermentation time by about 55% by comparison with the other supplementations. The stability of probiotic bacteria was weakly affected by milk supplementation and culture composition. However, pure cultures were more stable than mixed cultures. The texture of the fermented products was not dependent on culture composition, but strongly dependent on milk supplementation. Sweet whey supplementation gave products with lower firmness and viscoelasticity than products supplemented with casein hydrolysate or milk proteins (decrease by 70%). It was observed that all products containing probiotic counts over 2.2×107 CFU mL−1 are suitable for the development of a lactic beverage containing probiotics.
The aim of this study was to determine the effects of using various probiotic bacteria and plant oils in cultured cream on the fatty acid profiles including conjugated linoleic acids (CLA). L. acidophilus, B. bifidum, S. thermophilus and L. bulgaricus, P. thoenii (jensenii) P126, and P. jensenii B1264 and a mixed culture (blend of L. acidophilus, B. bifidum, S. thermophilus and L. bulgaricus) were used in the fermentation of cream samples at a level of 2%. Cream samples were fortified with sunflower oil, soybean oil and hazelnut oil at a level of 2%. Microbial counts and fatty acid profile analysis were performed. The microbial results demonstrated that fermented cream could be a superior product for the presence of probiotics. Even though the cream samples contained 52% milk fat, in the majority of the samples growth of probiotic bacteria was higher than 106 cfu/g. Concentrations of short-chain fatty acids such as butyric, caproic and capric acids in cultured cream samples differed depending on the cultures used, while long-chain unsaturated fatty acids were significantly affected by the plant oil fortification. The highest CLA content was obtained in the sample produced with B. bifidum, containing 0.73 mg of CLA/g fat. The effect of different plant oils on CLA concentration was significant (p >0.05) for HO + YC, SFO + LBYC and SO + LBYC. Results of the study are important for the dairy industry since it is the first publication on fermented cream with improved functional properties. The development of functional cultured cream with plant oils and probiotic bacteria would provide an important alternative dairy product.
The protection of human health as well as the quality and safe food assurance becomes the priority of European research in
the sphere of animal production. The negative experiences with the using of antibiotic growth promoters lead to subsequent
reduction of their application. It is necessary to replace them by the growth promoters of natural origin, which are able
to provide the comparable efficacy and will not contribute to the cumulative contamination of the environment. The probiotics
represent an effective alternative to antibiotics and current research should be aimed at improving of their efficacy. This
may be achieved by several methods. From the practical point of view, combination with synergistically acting components of
natural origin seems to be the best way. Potentiated probiotics are defined as biopreparations containing production strains
of microorganisms and synergistically acting components of natural origin which exert their intensified effect through effects
on probiotic and gut microorganisms, the gut mucosa and the intestinal environment or immune system. A number of suitable
components may be used for this purpose, such as prebiotics, non-specific substrates, plants and their extracts, metabolites
of microorganisms and polyunsaturated fatty acids. In this report, the results of application of natural feed additives in
animals are reviewed and their valuation for the enhancement of probiotic effectiveness is discussed.
Extraction of non-timber forest products (NTFPs) can provide important income for the inhabitants of tropical developing countries. The present research focuses on NTFP extraction in the Amazon estuary by evaluating the economics of managing açaí (Euterpe oleracea), a predominant palm species of the Amazon floodplains. The productivity, revenues and costs associated with traditional household management of açaí were examined in secondary forests and in homegardens. The present value of the net revenue (NPV) of lands managed for fruit and palm-heart was calculated at different distances from the central market of Belém, Pará, Brazil. Intensity of açaí management was dependent on distance from the market and household resources, ranging from simple collection in natural forest to intense cultivation. All calculations of revenues accounted for variation in prices due to seasonality of production. Açaí ws found to be a highly valuable production system even at high rates of interest. At a 15% interest rate, the net present values were US 4266–6930 ha−1 in homegardens.
A new method for measuring the activity of mesophilic and thermophilic lactic acid bacteria is proposed based on measuring the pH of cultures at extremely short intervals (30–90 s) during growth and calculating several kinetic parameters, i.e. the maximum acidification rate (Vm), the time and pH at which Vm occurred, the time or pH range during which the observed rates were greater than Vm/2. These were easily calculated by coupling the pH meter to a microcomputer.
Most probiotic lactobacilli adhere to intestinal surfaces, a phenomenon influenced by free polyunsaturated fatty acids (PUFA). The present study investigated whether free linoleic acid, gamma-linolenic acid, arachidonic acid, alpha-linolenic acid, or docosahexaenoic acid in the growth medium alters the fatty acid composition of lactobacilli and their physical characteristics. The most abundant bacterial fatty acids identified were oleic, vaccenic, and dihydrosterculic acids. PUFA, especially conjugated linoleic acid (CLA) isomers and gamma-linolenic, eicosapentaenoic, docosahexaenoic, and alpha-linolenic acids, also were identified in lactobacilli. When lactobacilli were cultured in MRS broth supplemented with various free PUFA, the incorporation of a given PUFA into bacterial fatty acids was clearly observed. Moreover, PUFA supplementation also resulted in PUFA-dependent changes in the proportions of other fatty acids; major interconversions were seen in octadecanoic acids (18:1), their methylenated derivatives (19:cyc), and CLA. Intermittent changes in eicosapentaenoic acid proportions also were noted. These results were paralleled by minor changes in the hydrophilic or hydrophobic characteristics of lactobacilli, suggesting that PUFA interfere with microbial adhesion to intestinal surfaces through other mechanisms. In conclusion, we have demonstrated that free PUFA in the growth medium induce changes in bacterial fatty acids in relation to the regulation of the degree of fatty acid unsaturation, cyclization, and proportions of CLA and PUFA containing 20 to 22 carbons. The potential role of lactobacilli as regulators of PUFA absorption may represent another means by which probiotics could redirect the delicate balance of inflammatory mediators derived from PUFA within the inflamed intestine.
The antioxidant capacities of 11 commercial and non-commercial samples of Euterpe oleracea Mart. (açaí) fruit pulp were studied with the total oxidant scavenging capacity assay in a modified and automated version against three reactive oxygen species. The antioxidant capacities of all purple açaí samples were found to be excellent against peroxyl radicals, good against peroxynitrite and poor against hydroxyl radicals compared with common European fruit and vegetable juices recently analysed. In all cases the correlation between sample concentration and antioxidant capacities was non-linear. The antioxidant capacities against all three reactive oxygen species of the fruit pulp from one white açaí variety were very low. The phenolic compounds in purple açaí fruit pulp were identified by high-performance liquid chromatography-mass spectrometry, and the two major anthocyanins, cyanidin-3-glucoside and cyanidin-3-rutinoside, were quantified by high-performance liquid chromatography-visible spectrometry. The contributions of the anthocyanins to the overall antioxidant capacities of the fruit were estimated to be only approximately 10%. Obviously, compounds not yet identified are responsible for the major part of the antioxidant capacities of the açaí fruit pulp.
Compact Dry TC qualifies as a rapid method kit for determining aerobic colony counts in foods. The plates are presterilized and contain culture medium and a cold-soluble gelling agent. The medium is rehydrated by inoculating 1 mL diluted sample into the center of the self-diffusible medium and allowing the solution to diffuse by capillary action. The plates can then be incubated and the colonies counted without any additional steps. The Compact Dry TC method was validated with 5 different raw meats. The performance tests were conducted at 35 degrees and 30 degrees C. In all required performance studies, no apparent differences were observed between the Compact Dry TC method and the Standard Pour Plate method (AOAC Official Method 966.23) for the detection level of aerobic microorganisms. For the accuracy claim (n = 60), a correlation factor of r2(35) = 0.9977 (35 degrees C) and r2(30) = 0.9932 (30 degrees C) could be assigned, as stated in the application for "Performance Tested Method." Quality consistency and storage robustness studies, showed no significant variations in plate count results with different production lots or plates of diverse storage age.
Euterpe oleraceae is a large palm tree indigenous to the Amazon River and its tributaries and estuaries in South America. Its fruit, known as acai, is of great economic value to native people. In this study, a standardized freeze-dried acai fruit pulp/skin powder was used for all analyses and tests. Among many findings, anthocyanins (ACNs), proanthocyanidins (PACs), and other flavonoids were found to be the major phytochemicals. Two ACNs, cyandin 3-glucoside and cyanidin 3-rutinoside were found to be predominant ACNs; three others were also found as minor ACNs. The total content of ACNs was measured as 3.1919 mg/g dry weight (DW). Polymers were found to be the major PACs. The concentration of total PACs was calculated as 12.89 mg/g DW. Other flavonoids, namely, homoorientin, orientin, isovitexin, scoparin, and taxifolin deoxyhexose, along with several unknown flavonoids, were also detected. Resveratrol was found but at a very low concentration. In addition, components including fatty acids, amino acids, sterols, minerals, and other nutrients were analyzed and quantified. Total polyunsaturated fatty acid, total monounsaturated fatty acid, and total saturated fatty acids contributed to 11.1%, 60.2%, and 28.7% of total fatty acid. Oleic acid (53.9%) and palmitic acid (26.7%) were found to be the two dominant fatty acids. Nineteen amino acids were found; the total amino acid content was determined to be 7.59% of total weight. The total sterols accounted for 0.048% by weight of powder. The three sterols B-sitosterol, campesterol, and sigmasterol were identified. A complete nutrient analysis is also presented. Microbiological analysis was also performed.
Atherosclerosis is a chronic inflammatory disease. We previously reported that a diet high in alpha-linolenic acid (ALA) reduces lipid and inflammatory cardiovascular disease risk factors in hypercholesterolemic subjects.
The objective was to evaluate the effects of a diet high in ALA on serum proinflammatory cytokine concentrations and cytokine production by cultured peripheral blood mononuclear cells (PBMCs) from subjects fed the experimental diets.
A randomized, controlled, 3-diet, 3-period crossover study design was used. Hypercholesterolemic subjects (n = 23) were assigned to 3 experimental diets: a diet high in ALA (ALA diet; 6.5% of energy), a diet high in linoleic acid (LA diet; 12.6% of energy), and an average American diet (AAD) for 6 wk. Serum interleukin (IL)-6, IL-1beta, and tumor necrosis factor-alpha (TNF-alpha) concentrations and the production of IL-6, IL-1beta, and TNF-alpha by PBMCs were measured.
IL-6, IL-1beta, and TNF-alpha production by PBMCs and serum TNF-alpha concentrations were lower (P < 0.05 and P < 0.08, respectively) with the ALA diet than with the LA diet or AAD. PBMC production of TNF-alpha was inversely correlated with ALA (r = -0.402, P = 0.07) and with eicosapentaenoic acid (r = -0.476, P = 0.03) concentrations in PBMC lipids with the ALA diet. Changes in serum ALA were inversely correlated with changes in TNF-alpha produced by PBMCs (r = -0.423, P < 0.05).
Increased intakes of dietary ALA elicit antiinflammatory effects by inhibiting IL-6, IL-1beta, and TNF-alpha production in cultured PBMCs. Changes in PBMC ALA and eicosapentaenoic acid (derived from dietary ALA) are associated with beneficial changes in TNF-alpha release. Thus, the cardioprotective effects of ALA are mediated in part by a reduction in the production of inflammatory cytokines.
Almost all foods contain fat, which is very loosely de ned as material that is soluble in any of several organic solvents such as hexane, diethyl ether, or chloroform. The major lipid classes commonly encountered in foods are shown in Figure 3.1. For this discussion, pigments, sterols, hydrocarbons, tocopherols, waxes, and so on will be ignored, although they are coextracted along with the major classes of lipids. The distinguishing feature of lipids in foods is the universal occurrence of medium-and long-chain (C14-C22) fatty acids. The hydrocarbon chains of these fatty acids are the main factor in the solubility already mentioned. As emphasized by the adjectives, the nomenclature is rather confused. Most nutritionists distinguish the C8, C10, and C12 fatty acids from the common C16 and C18 fatty acids by calling the former short chain and the latter long chain. The former are readily digested, and on absorption they pass directly to the liver via the portal vein, whereas the latter tend to transfer into the lymph in chylomicrons (Nelson and Ackman, 1988). For most foods, C22 fatty acids are the longest chain length present in any quantity, and in this chapter, long chain will mean C20 and C22.
This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bacteria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree values than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.
Effects of various antibiotics and of addition of various sugars as sole carbon source to minimal nutrient agar base were studied in order to develop a simple and reliable method for selective enumeration of L acidophilus in yogurt containing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, L. acidophilus, and Bifidobacterium spp. Application of antibiotics was found to be unsuitable for selective enumeration of L acidophilus. Use of salicin as a sole carbon source in the minimal nutrient base medium was found to suppress the growth of all the 4 groups of bacteria studied except that of L. acidophilus. Salicin medium was successfully used for selective enumeration of L acidophilus from pure cultures and from yogurts containing the 4 groups of lactic acid bacteria.
Fruit-flavoured yoghurt was made by adding 2.5, 5.0, 7.5 and 10.0% mulberry pekmez (MP) into milk. The effects of the MP on the quality and fermentation process of the yoghurt were determined. The titratable acidity, pH, viscosity, whey separation and lactic acid bacteria (LAB) counts were determined at weekly intervals for 28 days. The pH range of the MP yoghurts was 4.65–5.57 and the pH of the plain yoghurt was 4.47 (P < 0.05). The addition of MP led to an increase in the fermentation time and a decrease in the viscosity of the yoghurts. Statistically significant differences were found between the plain and MP yoghurts in terms of pH (4.01 and 4.35), viscosity (5429 and 3175 cP) and number of LAB (7.07 and 6.48 log cfu). During storage, the titratable acidity, viscosity and LAB counts of MP yoghurts were lower and the whey separations higher than those of controls.
The benefits of probiotics have been recognized and explored for over a century. The pioneering work of Tissier and Moro was elaborated in the Metchnikoff's theory of longevity and converted into commercial reality by Shirota and Kellogg in 1930s and German nutritionists with their probiotic therapy in 1950s. Our knowledge about probiotics and their interactions with the host has grown ever since and many potential and even proven mechanisms of action for probiotics have recently been published. Definitely, there is enough clinical evidence to support certain health claims attributed to selected strains of Lactobacillus and Bifidobacterium spp. However, substantial work needs to be done to substantiate other potentially beneficial properties including immunomodulation, hypocholesterolemic and anticarcinogenic effects. The aim of this review is to pay the tribute to pioneers in the field and provide an overview of the current state of knowledge about probiotics and their impact on our well-being.
The production of free fatty acids (FFAs) and conjugated linoleic acid (CLA) in probiotic dahi containing Lactobacillus acidophilus and L. casei during fermentation and 10d of storage at 4°C was evaluated and compared with control dahi. The total FFAs in terms of acid degree values significantly increased during fermentation and storage of both types of dahi samples. In addition, gas chromatographic analysis of FFAs showed that butyric and linoleic acids increased in the probiotic dahi compared to control dahi during fermentation and storage. Furthermore, the CLA content increased in probiotic dahi during fermentation and remained stable during storage, whereas no change was observed in the control dahi. Probiotic lactobacilli appeared to increase the production of FFAs by lipolysis of milk fat, and produced CLA by using internal linoleic acid, which may confer nutritional and therapeutical value to the product.
The viability of Lactobacillus acidophilus LAFTI® L10, Bifidobacterium lactis LAFTI® B94, and L. paracasei LAFTI® L26 and their proteolytic activities were assessed in yoghurt at different termination pH of 4.45, 4.50, 4.55, and 4.60 in the presence of L. delbrueckii ssp. bulgaricus Lb1466 and Streptococcus thermophilus St1342 during 28 days of storage at 4°C. All strains achieved the recommended level of 6.00logcfug−1 of the product with L. acidophilus LAFTI® L10 and L. paracasei LAFTI® L26 exceeding the number to 8.00 and 7.00logcfug−1, respectively. Lactobacilli strains showed a good cellular stability maintaining constant concentration throughout storage period regardless of termination pH. On the other hand, the cell counts of B. lactis LAFTI® B94 decreased by one log cycle at the end of storage. The presence of probiotic organisms enhanced proteolysis significantly in comparison with the control batch containing L. delbrueckii ssp. bulgaricus Lb1466 and S. thermophilus St1342 only. The proteolytic activity varied due to termination pH, but also appeared to be strain related. The increased proteolysis improved survival of L. delbrueckii ssp. bulgaricus Lb1466 during storage resulting in lowering of pH and production of higher levels of organic acids, which might have caused the low cell counts for B. lactis LAFTI® B94.
The conjugated linoleic acid (CLA) isomers present in milk fat have a high health amelioration potential. Their high prevalence in fat of ruminants and in milk and dairy products has been described and confirmed over many years. The CLA isomers are formed during biohydrogenation of linoleic acid in the rumen and also through conversion of vaccenic acid in the mammary gland. In addition, several strains of Lactobacillus, Propionibacterium, Bifidobacterium and Enterococcus are able to form CLA from linoleic acid and thus could be used to increase the CLA level in fermented dairy products such as yoghurt and cheese. It appears likely that lactic acid bacteria and especially propionibacteria can form CLA during cheese ripening because free linoleic acid is formed in the ripening process. However, for the time being the reviewed data allow no final conclusion on whether these increased levels of CLA are mainly due to formation by microorganisms, or due to cattle feed or breed. Further studies including all these parameters will be necessary to elucidate the potential role of starter cultures to achieve physiologically relevant CLA levels in dairy products. It appears that contribution of presently used dairy starter bacteria to increased CLA content in cheese is relatively minor.
The effect of commercial fruit preparations (mango, mixed berry, passion fruit and strawberry) on the viability of probiotic bacteria, Lactobacillus acidophilus LAFTI® L10 and Bifidobacterium animalis ssp. lactis LAFTI® B94 in stirred yogurts during storage (35 days) at refrigerated temperature (4°C) was evaluated. The results showed that addition of either 5 or 10g/100g fruit preparations had no significant (p>0.05) effect on the viability of the two probiotic strains except on L. acidophilus LAFTI L10 yogurt with 10g/100g passion fruit or mixed berry. After the addition of fruit preparation, 96% of the yogurts incorporated with fruit preparation did not exhibit a greater loss in the viability of probiotic bacteria compared to plain yogurt during the storage period. A correlation between the post-storage pH in yogurts and the survival of probiotic bacteria was observed. All the yogurts, however, contained the recommended levels of (106–107cfu/g) probiotic bacteria at the end of 35-day shelf life.
Ever-growing consumer demand for convenience, combined with a healthy diet and preference for natural ingredients has led to a growth in functional beverage markets. Current trends and changing consumer needs indicate a great opportunity for innovations and developments in fermented milks. Scientific and clinical evidence is also mounting to corroborate the consumer perception of health from fermented milks. Probiotics, prebiotics, synbiotics and associated ingredients also add an attractive dimension to cultured dairy products. Also, owing to expanding market share and size of dairy companies, there has been a reduction of clearly structured markets i.e. merging of dairy products and fruit beverage markets with introduction of `juiceceuticals' like fruit-yogurt beverages that are typical example of hybrid dairy products offering health, flavour and convenience. Another potential growth area for fermented milks includes added-value products such as low calorie, reduced-fat varieties and those fortified with physiologically active ingredients including fibers, phytosterols, omega-3-fatty acids, whey based ingredients, antioxidant vitamins, isoflavones that provide specific health benefits beyond basic nutrition. World over efforts have been devoted to develop fermented milks containing certain nonconventional food sources like soybeans and millets and convert them to more acceptable and palatable form thus producing low cost, nutritious fermented foods especially for developing and underdeveloped nations where malnutrition exists. Furthermore, use of biopreservatives and certain innovative technologies like membrane processing, high pressure processing and carbonation lead to milk fermentation under predictable, controllable and precise conditions to yield hygienic fermented milks of high nutritive value.
The aim of this work was to evaluate the suitability of yogurt containing açaí pulp as a food carrier of probiotic cultures. Probiotic yogurts containing increasing amounts of açaí pulp (3, 5 and 7%) were processed and submitted to a physicochemical analysis and viable microbial count during refrigerated storage. In general, all the physicochemical parameters showed variations proportional to the amount of açaí pulp in the product formulation. Probiotic activity was verified throughout refrigerated storage for all the products, although there was a fall of one logarithmic cycle for both micro-organisms during this period (107–108 CFU/mL).
We examined the effect of storage time on culture viability and some rheological properties (yield stress, storage modulus, loss modulus, linear viscoelastic region, structural recuperation and firmness) of fermented milk made with Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus (LA) and Bifidobacterium animalis ssp. lactis in coculture with Streptococcus thermophilus (ST). Acidification profiles and factors that affect viability (postfermentation acidification, acidity and dissolved oxygen) were also studied during 35 days at 4C. Fermented milk prepared with a coculture of ST and Bifidobacterium lactis gave the most constant rheological behavior and the best cell viability during cold storage; it was superior to ST plus LA for probiotic fermented milk production.
Probiotic cultures should grow quickly in milk, provide adequate sensory and rheological properties to the product, and remain viable during storage. Commercially, it is very common to use yogurt starter culture (i.e. Streptococcus thermophilus[ST] and Lactobacillus delbrueckii ssp. bulgaricus) in combination with the probiotic bacteria in order to reduce fermentation time. However, LB tends to post acidify fermented milk, which reduces the viability of the probiotic bacteria; thus, it is recommended to use starter cultures devoid of this species. We found that the technological properties and the viability of the probiotic bacterium Bifidobacterium animalis ssp. lactis BL O4 in coculture with ST make it suitable for probiotic fermented milk production; it produces rheological characteristics similar to those of yogurt.
The objectives of this study were to identify the factors and procedures responsible for increasing the conjugated linoleic acid (CLA) content in fermented milk. Fourteen lactic acid bacteria were screened for CLA-producing ability using sunflower oil (containing 70% linoleic acid) as a substrate. Among the screened strains, Lactococcus lactis I-01 showed the highest CLA-producing ability. The optimal concentration of sunflower oil for CLA production was 0.1 g/L in whole milk, which accounted for 0.25% of total milk fat. Our results demonstrated that CLA formation in fermented milk could be affected by numerous factors such as bacterial strain, cell number, optimal substrate concentration, and the period of incubation at neutral pH.
The establishment of the intestinal microflora, and probiotic bacteria, may control the inflammatory conditions in the gut. As polyunsaturated fatty acids (PUFA) possess antimicrobial activities, they may deter the action of probiotics. We assessed whether free linoleic, γ-linolenic, arachidonic, α-linolenic and docosahexaenoic acids at physiological concentrations in the growth media would influence the growth and adhesion of Lactobacillus GG (probiotic), Lactobacillus casei Shirota (probiotic) and Lactobacillus bulgaricus (dairy strain). Higher concentrations of PUFA (10–40 μg PUFA ml−1) inhibited growth and mucus adhesion of all tested bacterial strains, whilst growth and mucus adhesion of L. casei Shirota was promoted by low concentrations of γ-linolenic acid and arachidonic acid (at 5 μg ml−1), respectively. PUFA also altered bacterial adhesion sites on Caco-2 cells. Caco-2 cells grown in the presence of arachidonic acid were less adhered to by all three bacterial strains. Yet, L. casei Shirota adhered better on Caco-2 cells grown in the presence of α-linolenic acid. As the adhesion to mucosal surfaces is pivotal in health promoting effects by probiotics, our results indicate that the action of probiotics in the gut may be modulated by dietary PUFA.
Fruit yogurt was prepared by adding concentrated grape juice (pekmez) CGJ, to milk. Optimum CGJ concentration and its influence on quality and fermentation process of yogurt were evaluated. The pH, titratable acidity, protein content, viscosity, whey syneresis, starter bacteria, mold and yeast counts were determined weekly at 4°C for 1 month. Addition of 10% CGJ provided desired sweetness. After 4h incubation of 5–10–15% CGJ-added yogurts the pH was 4.44, 4.98 and 5.90, respectively, and the control was pH 4.26. CGJ addition increased fermentation time and decreased viscosity. During storage, acidity of 10% CGJ-added yogurt remained lower (P<0.05) than controls. CGJ did not affect (P>0.05) protein content and molds or yeasts were not detected.
Crude and refined hazelnut oils from different countries were characterised by major and minor compounds. Fatty acids, triacylglycerides, waxes, sterols, methyl-sterols, terpenic and aliphatic alcohols, tocopherols, tocotrienols and hydrocarbons were identified and quantified by gas chromatography and high-performance liquid chromatography. The levels of these chemical compounds in hazelnut oils together with the equivalent carbon numbers and triacylglyceride carbon numbers, were compared with the results of analyses of samples of other vegetable oils. The statistical procedure of cluster analysis was used to characterise hazelnut oils versus other edible oils.
The growth and metabolism of two probiotic organisms (L. acidophilus LAFTI® L10 and Lactobacillus casei LAFTI® L26) and a regular yoghurt culture (L. delbrueckii ssp. bulgaricus Lb1466 and Streptococcus thermophilus St1342) were studied in yoghurt containing 0.5%, 1.0%, and 1.5% (w/v) of high amylose corn starch powder (Hi-maize®) or inulin. Viable cell counts of probiotic organisms, their metabolites and proteolytic activities, and viscosity of the yoghurts were determined during refrigerated storage for 28 d at 4 oC. In the presence of inulin, cultures showed better retention of viability (8.0 log cfu g−1) in comparison with that of Hi-maize, which had a reduction by one log cycle. Lower concentrations of 0.5–1.0% Hi-maize improved (P<0.05) the production of propionic acid and also increased proteolytic activity of probiotic organisms substantially. A greater release of free amino acids may have sustained better growth of the organisms in yoghurts. Supplementation with either Hi-maize or inulin increased the viscosity of probiotic yoghurts significantly (P<0.05).
A survey was carried out to determine the content of conjugated linoleic acid (CLA) in various dairy products. The only detected CLA isomer was cis-9trans-11 linoleic acid. Commercial samples of yoghurt, fermented milk and cheese were analyzed: 16 standard yoghurts, 6 organic yoghurts, 8 mountain pasture yoghurts, 5 sheep yoghurts, 8 probiotic yoghurts, 8 fermented milk samples, 6 fermented milk samples from mountain pastures, 30 cow cheeses (9 Alpine cheeses, 8 Swiss Emmental, 8 Fontina Valdostana, 5 Grana Padano and Parmigiano Reggiano), 12 ewe cheeses (Pecorino) and 8 goat cheeses. The fatty acid composition and fat content were also assessed. Fontina Valdostana had the highest amount of CLA (8.11 mg/g fat), followed by Pecorino cheese (7.77 mg/g fat), Swiss Emmental (7.66 mg/g fat) and sheep yoghurt (6.92 mg/g fat). High levels of CLA were also found in fermented milk and yoghurt of mountain pasture and organic yoghurt (6.15, 6.06 and 6.05 mg/g fat, respectively). The animal diet, specific characteristics of the milk used in manufacturing, with special reference to the species and CLA content of the milk, processing and production methods play an important role in setting the CLA levels in dairy products.
Probiotics could represent an effective alternative to the use of synthetic substances in nutrition and medicine. The data concerning the efficacy of probiotics are often contradictory and it will be important to search for ways to improve their efficacy. In order to enhance the efficacy of probiotics, it is necessary to obtain additional knowledge on their mode of action. The efficacy of probiotics may be potentiated by the several methods: the selection of more efficient strains; gene manipulation; the combination of several strains; and the combination of probiotics and synergistically acting components. This review focuses on the enhancement of the efficacy of probiotics by their combination with synergistically acting components of natural origin. This approach seems to be the best way of potentiating the efficacy of probiotics and is widely used in practise. By the above-mentioned method, more effective probiotic preparations will be developed.
Nine probiotic lactobacilli strains were evaluated for their ability to survive in a commercial fruit drink stored at 4 °C for up to 80 days. The pH of the drink was 4.2, which enabled good stability of many cultures during storage. Lactobacillus rhamnosus seemed more stable than Lactobacillus acidophilus in this medium, but viability was still mostly strain dependent. Spectrophotometry studies showed that the cultures generally had higher growth rates as pH increased from 3.8 to 4.2. There was a correlation (P = 0.037) between stability during storage in the drink and the ability of the strains to grow at pH 4.2, but that the relationship was not strong (R2 = 0.49). Four strains were selected to study their resistance to simulated gastro-intestinal (GI) conditions. Fresh cultures were compared to those obtained after 35 days of storage at 4 °C. Viability in presence of 0.3% bile salts or of pancreatic enzymes was not affected by previous refrigerated storage. However, the cultures which were tested after having been stored for 35 days at 4 °C in the fruit drink had on the average 1.2 log higher viability losses than the fresh cultures when exposed to a 2 h incubation at pH 2.0 to simulate a gastric stress.
This study investigates the kinetics of acidification, fatty acid (FA) profile and conjugated linoleic acid (CLA, C18:2 c9, t11) content in fermented milks prepared from organic and conventional milk. Fermented milks were manufactured with five mixed cultures: four different strains of Bifidobacterium animalis subsp. lactis (BL04, B94, BB12 and HN019) and Lactobacillus delbrueckii subsp. bulgaricus LB340, in co-culture with Streptococcus thermophilus TA040. The composition of milk was evaluated, and the kinetics of acidification was followed by continuous pH measurement using the Cinac system. The profile of FA, including CLA, was analyzed by gas chromatography. The chemical composition of conventional and organic milk was similar, with the exception of protein and Fe, the concentrations of which were higher in the organic milk. The rate of acidification was significantly influenced by the type of milk and the bacterial strain used. Co-cultures St-HN019 and St-BB12 showed higher maximal acidification rates in both milks. Final counts of S. thermophilus (9.0-10.1 log10 colony forming units (CFU)·mL-1), Lactobacillus bulgaricus (8.2-8.5 log 10 CFU·mL-1) and B. animalis subsp. lactis strains (8.3-9.3 log10 CFU·mL-1) did not differ significantly in either milk. Unexpectedly, all fermented organic milks contained significantly higher amounts of CLA than the same milk before fermentation, whereas CLA amounts did not change during fermentation of conventional milk. Regardless of the type of milk, CLA was found to be significantly positively correlated with trans-vaccenic acid and negatively correlated with linoleic acid. Moreover, the CLA contents were significantly higher in fermented milks showing shorter fermentation times.
The simultaneous effects of different binary co-cultures of Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus rhamnosus and Bifidobacterium lactis with Streptococcus thermophilus and of different prebiotics on the production of fermented milk were investigated in this paper. In particular, we determined and compared the kinetics of acidification of milk either as such or supplemented with 4% (w/w) maltodextrin, oligofructose and polydextrose, as well as the probiotic survival, chemical composition (pH, lactose, lactic acid and protein contents), fatty acids profile and conjugate linoleic acid (CLA) content of fermented milk after storage at 4 degrees C for 24 h. Fermented milk quality was strongly influenced both by the co-culture composition and the selected prebiotic. Depending on the co-culture, prebiotic addition to milk influenced to different extent kinetic acidification parameters. All probiotic counts were stimulated by oligofructose and polydextrose, and among these B. lactis always exhibited the highest counts in all supplemented milk samples. Polydextrose addition led to the highest post-acidification. Although the contents of the main fatty acids were only barely influenced, the highest amounts of conjugated linoleic acid (38% higher than in the control) were found in milk fermented by S. thermophilus-L. acidophilus co-culture and supplemented with maltodextrin.
The acai berry is the fruit of the acai palm and is traditionally consumed in Brazil but has gained popularity abroad as a food and functional ingredient, yet little information exists on its health effect in humans. This study was performed as an acute four-way crossover clinical trial with acai pulp and clarified acai juice compared to applesauce and a non-antioxidant beverage as controls. Healthy volunteers (12) were dosed at 7 mL/kg of body weight after a washout phase and overnight fast, and plasma was repeatedly sampled over 12 h and urine over 24 h after consumption. Noncompartmental pharmacokinetic analysis of total anthocyanins quantified as cyanidin-3-O-glucoside showed Cmax values of 2321 and 1138 ng/L at t max times of 2.2 and 2.0 h, and AUC last values of 8568 and 3314 ng h L(-1) for pulp and juice, respectively. Nonlinear mixed effect modeling identified dose volume as a significant predictor of relative oral bioavailability in a negative nonlinear relationship for acai pulp and juice. Plasma antioxidant capacity was significantly increased by the acai pulp and applesauce. Individual increases in plasma antioxidant capacity of up to 2.3- and 3-fold for acai juice and pulp, respectively were observed. The antioxidant capacity in urine, generation of reactive oxygen species, and uric acid concentrations in plasma were not significantly altered by the treatments. Results demonstrate the absorption and antioxidant effects of anthocyanins in acai in plasma in an acute human consumption trial.
Fifteen media were evaluated to determine their suitability for selective enumeration of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and bifidobacteria using 5 to 6 strains of each of the four groups of organisms. Streptococcus thermophilus agar was found to be suitable for selective enumeration of S. thermophilus under aerobic incubation at 37 degrees C for 24 h. The MRS agar at pH 5.2 or reinforced clostridial agar at pH 5.3 could be used for the selective enumeration of L. delbrueckii ssp. bulgaricus when the incubation was carried out at 45 degrees C for > or = 72 h. However, the recovery of this organism was lower on MRS agar at pH 5.2 or reinforced clostridial agar at pH 5.3 than that obtained on MRS agar. The recovery of L. acidophilus and bifidobacteria on MRS agar and MRS-maltose agar was similar; MRS-maltose agar could be used to enumerate total counts of L. acidophilus and bifidobacteria. For selective enumeration of L. acidophilus, MRS-salicin agar or MRS-sorbitol agar could be used. For selective enumeration of bifidobacteria, MRS NNLP (nalidixic acid, neomycin sulfate, lithium chloride, and paromomycin sulfate) agar was suitable; however, determination of bifidobacteria by differential counts between L. acidophilus enumerated on MRS-salicin agar or MRS-sorbitol agar and the total counts of L. acidophilus and bifidobacteria obtained from MRS-maltose agar resulted in higher recovery of some strains of bifidobacteria. Other media that were evaluated in this study were not suitable for selective enumeration.
The establishment of the intestinal microflora, and probiotic bacteria, may control the inflammatory conditions in the gut. As polyunsaturated fatty acids (PUFA) possess antimicrobial activities, they may deter the action of probiotics. We assessed whether free linoleic, gamma-linolenic, arachidonic, alpha-linolenic and docosahexaenoic acids at physiological concentrations in the growth media would influence the growth and adhesion of Lactobacillus GG (probiotic), Lactobacillus casei Shirota (probiotic) and Lactobacillus bulgaricus (dairy strain). Higher concentrations of PUFA (10-40 microg PUFA ml(-1)) inhibited growth and mucus adhesion of all tested bacterial strains, whilst growth and mucus adhesion of L. casei Shirota was promoted by low concentrations of gamma-linolenic acid and arachidonic acid (at 5 microg ml(-1)), respectively. PUFA also altered bacterial adhesion sites on Caco-2 cells. Caco-2 cells grown in the presence of arachidonic acid were less adhered to by all three bacterial strains. Yet, L. casei Shirota adhered better on Caco-2 cells grown in the presence of alpha-linolenic acid. As the adhesion to mucosal surfaces is pivotal in health promoting effects by probiotics, our results indicate that the action of probiotics in the gut may be modulated by dietary PUFA.
I investigated whether there is a common link between essential fatty acids and probiotics, which have similar actions and benefits in atopy.I made a critical review of the literature pertaining to the actions of essential fatty acids and probiotics on immune response and the interaction between them with particular reference to atopy.Colonization of the human gastrointestinal tract occurs in the first months and years of life. Probiotics are cultures of beneficial bacteria of healthy gut microflora, which reduce dietary antigen load and thus protect against atopy. A significant reduction in the risk of childhood asthma and other atopic conditions was reported in children who were exclusively breast-fed for at least 4 mo after birth. This beneficial action can be attributed to the immunomodulatory, nutritional, or other components of human milk Human breast milk is rich in long-chain polyunsaturated fatty acids (LCPUFAs), which have immunomodulatory actions. Probiotics and LCPUFAs modulate T-helper 1 and 2 responses, show antibioticlike actions, and alleviate changes related to allergic inflammation. LCPUFAs promote the adhesion of probiotics to mucosal surfaces, which augments the health-promoting effects of probiotics. In view of the similarity in their actions and because LCPUFAs promote the actions of probiotics, I believe that a combination of LCPUFAs and probiotics offer significant protection against atopy. It is likely that breast-feeding and probiotics are two naturally occurring, appropriate events in early human life that have significant health benefits.
Short-chain fatty acid (SCFA) formation by intestinal bacteria is regulated by many different host, environmental, dietary and microbiological factors. In broad terms, however, substrate availability, bacterial species composition of the microbiota and intestinal transit time largely determine the amounts and types of SCFA that are produced in healthy individuals. The majority of SCFA in the gut are derived from bacterial breakdown of complex carbohydrates, especially in the proximal bowel, but digestion of proteins and peptides makes an increasing contribution to SCFA production as food residues pass through the bowel. Bacterial hydrogen metabolism also affects the way in which SCFA are made. This outcome can be seen through the effects of inorganic electron acceptors (nitrate, sulfate) on fermentation processes, where they facilitate the formation of more oxidised SCFA such as acetate, at the expense of more reduced fatty acids, such as butyrate. Chemostat studies using pure cultures of saccharolytic gut micro-organisms demonstrate that C availability and growth rate strongly affect the outcome of fermentation. For example, acetate and formate are the major bifidobacterial fermentation products formed during growth under C limitation, whereas acetate and lactate are produced when carbohydrate is in excess. Lactate is also used as an electron sink in Clostridium perfringens and, to a lesser extent, in Bacteroides fragilis. In the latter organism acetate and succinate are the major fermentation products when substrate is abundant, whereas succinate is decarboxylated to produce propionate when C and energy sources are limiting.
A gas chromatographic procedure was used for analysis of conjugated linoleic acid (CLA) isomers cis-9, trans-11-octadecadienoic; trans-10, cis-12 octadecadienoic; and trans-9, trans-11-octadecadienoic (c9t11, t10c12, t9t11) produced by lactobacilli. Four different cultures, two strains each of Lactobacillus acidophilus and Lactobacillus casei were tested for their ability to produce CLA from free linoleic acid in MRS broth supplemented with linoleic acid. Different concentrations of linoleic acid (0, 0.05, 0.1, 0.2 and 0.5 mg/ml) were added to MRS broth, inoculated with the lactobacilli, and incubated at 37 degrees C. Viable counts and amounts of individual isomers of CLA (c9t11, t10c12, t9t11) were measured at 0, 24, 48, and 72 h. All the cultures were able to produce free CLA in media supplemented with linoleic acid. Maximum production of CLA (80.14 to 131.63 microg/ml) was observed at 24 h of incubation in broth containing 0.02% of free linoleic acid. No significant (P > 0.05) increases in total CLA levels were observed after 24 h of incubation. The ability of the cultures to produce CLA in skim milk supplemented with 0.02% free linoleic acid also was studied. In this medium, the total amounts of free CLA after 24 h of incubation ranged from 54.31 to 116.53 microg/ml. The use of lactic acid bacteria able to form free CLA in cultured dairy products may have potential health or nutritional benefits. Free CLA in the products likely would be more readily available for absorption from the digestive tract than if it were incorporated into the cells of the starter culture.
This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bacteria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree values than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.
Conjugated fatty acids have attracted much attention as a novel type of biologically beneficial functional lipid. Some isomers of conjugated linoleic acid (CLA) reduce carcinogenesis, atherosclerosis, and body fat. Considering the use of CLA for medicinal and nutraceutical purposes, a safe isomer-selective process is required. The introduction of biological reactions for CLA production could be an answer. We screened microbial reactions useful for CLA production, and found several unique reactions in lactic acid bacteria. Lactic acid bacteria produced CLA from linoleic acid. The produced CLA comprised a mixture of cis-9,trans-11-octadecadienoic acid (18:2) and trans-9,trans-11-18:2. Lactobacillus plantarum AKU 1009a was selected as a potential CLA producer. Using washed cells of L. plantarum AKU 1009a as a catalyst, CLA production from linoleic acid reached 40 mg/ml under the optimized conditions. The CLA-producing reaction was found to consist of two successive reactions, i.e., hydration of linoleic acid to 10-hydroxy-12-octadecenoic acid and dehydrating isomerization of the hydroxy fatty acid to CLA. On the basis of these results, the transformation of hydroxy fatty acids by lactic acid bacteria was investigated. Lactic acid bacteria transformed ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid) to CLA (a mixture of cis-9,trans-11-18:2 and trans-9,trans-11-18:2). Castor oil, which is rich in the triacylglycerol form of ricinoleic acid, was also found to act as a substrate for CLA production by lactic acid bacteria with the aid of lipase-catalyzed triacylglycerol hydrolysis. L. plantarum AKU 1009a produced conjugated trienoic fatty acids from alpha- and gamma-linolenic acid. The trienoic fatty acids produced from alpha-linolenic acid were identified as cis-9,trans-11,cis-15-octadecatrienoic acid (18:3) and trans-9,trans-11,cis-15-18:3. Those produced from gamma-linolenic were cis-6,cis-9,trans-11-18:3 and cis-6,trans-9,trans-11-18:3. The conjugated trienoic fatty acids produced from alpha- and gamma-linolenic acid were further saturated by L. plantarum AKU 1009a to trans-10,cis-15-18:2 and cis-6,trans-10-18:2, respectively.
As the health benefits of ingesting live bacteria become more evident, foods are now being produced that contain probiotic bacteria. The data to support label health claims for probiotic products are often difficult to provide. The experimental evidence to identify probiotic microorganisms and to demonstrate their efficacy in clinical trials is more challenging than for other potential functional foods because effects are mediated by living microorganisms and may therefore be influenced by the status of these microorganisms. Clinical trials to show efficacy are expensive. Obtaining appropriate samples is difficult. A scientific consensus is building to support the claim that the ingestion of certain probiotic bacteria reduces lactose intolerance and can reduce the duration of rotavirus diarrheas. Some probiotic bacteria have "generally accepted as safe" status; proof of the safety of any probiotic is essential. Japanese health regulatory officials, using their Foods for Specific Health Use system, have approved human health claims for over 20 probiotic products. On the other hand, at this time, no probiotic product is sold in Canada that carries a label health claim. This illustrates the considerable discrepancies across countries in perception of health effects of probiotics.
Ana ´lise dos retornos sociais oriundos de adoça ˜o tecnolo ´gica na cultura do açai no estado do Para ´. Amazo ˆnia: Cie ˆncia e Desenvolvimento Automatic method to quantify starter activity based on pH measurement Probiotics – from Metchnikoff to bioactives
- I M Silva
- A C Santana
- M S Reis
International Dairy Journal, 14, 1–15. Silva, I. M., Santana, A. C., & Reis, M. S. (2006). Ana ´lise dos retornos sociais oriundos de adoça ˜o tecnolo ´gica na cultura do açai no estado do Para ´. Amazo ˆnia: Cie ˆncia e Desenvolvimento, 2, 25–37. Spinnler, H. E., & Corrieu, G. (1989). Automatic method to quantify starter activity based on pH measurement. Journal of Dairy Research, 56, 755–764. Vasiljevic, T., & Shah, N. P. (2008). Probiotics – from Metchnikoff to bioactives
Increased CLA content in organic milk fermented by bifidobacteria or yoghurt cultures Milk and milk products – Extraction methods for lipids and liposoluble compounds. ISO standard 14156: International Organiza-tion for Standardization Milk fat – Preparation of fatty acid methyl esters
- A C Florence
- R C Silva
- Espı
- A P Santo
- L A Gioielli
- A Y Tamime
- M N Oliveira
Florence, A. C., Silva, R. C., Espı ´rito Santo, A. P., Gioielli, L. A., Tamime, A. Y., & Oliveira, M. N. (2009). Increased CLA content in organic milk fermented by bifidobacteria or yoghurt cultures. Dairy Science and Technology, 89, 541–553. ISO. (2001). Milk and milk products – Extraction methods for lipids and liposoluble compounds. ISO standard 14156. Geneva, Switzerland: International Organiza-tion for Standardization. ISO. (2002). Milk fat – Preparation of fatty acid methyl esters. ISO Standard 15884
B94 and B. longum Bl05 in Reinforced Clostridial Agar plus 100 mL mL À1 dicloxacillin Antibiotics were employed to allow selective growth of bifidobacteria. M17 and MRS media (pH 5.4) were prepared according to Jordano Cell concentration was expressed as
- Dave
- Shah
plus 10 mL mL À1 clindamycin, and Bifidobacterium lactis B04, B94 and B. longum Bl05 in Reinforced Clostridial Agar plus 100 mL mL À1 dicloxacillin. Antibiotics were employed to allow selective growth of bifidobacteria. M17 and MRS media (pH 5.4) were prepared according to Jordano, Serrano, Torres, and Salmeron (1992) and Dave and Shah (1996), respectively, and MRS plus clindamycin according to Lankaputhra and Shah (1996). Cell concentration was expressed as log cfu mL À1 of fermented milk.