Donkey Milk for Manufacture of Novel Functional Fermented Beverages

The aim of this work was to investigate on the functional features of a donkey milk probiotic berevage as a novel food. Particularly, it was to study the decrease of lactose content and the antioxidant activity of standard yogurt (YC) and probiotic yogurt (YP; Lactobacillus acidophilus, Lactobacillus casei) from donkey milk during the storage up to 30 d at 4 ºC. The evolution of lactose content using enzymatic‐spectrophotometric kits was analyzed. Antioxidant activity of yogurt was measured using 2,2’‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), and thiol assays. Parallel consumer sensory studies were carried out as consumer test in order to gain information about the impact of these novel fermented beverages on sensory perceptions. The statistical analysis has shown significant effect of studied factors. The results showed that the lactose content gradually decreased during storage in both yogurts, reaching values of 2.36% and 2.10% in YC and YP, respectively, at 30 d (P < 0.05). During storage of both yogurt types, the antioxidant activity increased, but YP showed a higher antioxidant activity than YC. The results suggest that the antioxidant activity of yogurt samples was affected by cultures of lactic acid bacteria (LAB). We conclude that the fermented donkey milk could be configured as health and nutraceutical food, which aims to meet nutritional requirements of certain consumers groups with lactose or cow milk protein intolerance.     

Survival of probiotic bifidobacteria in buffalo curd and their effect on sensory properties

The feasibility of incorporating Bifidobacterium longum NCTC11818 in buffalo curd to produce a probiotic product was investigated. Fermentation at tropical ambient temperature (29 ± 2 °C), two storage temperatures (29 ± 2 °C and 4 ± 2 °C), and in three packaging materials (clay pots, plastic cups, and glass bottles) was investigated. Bifidobacteria survived for 3 days above the required population level of 10⁶ CFU g^?1 in buffalo curd packed in clay pots at 29 ± 2 °C. They did not persist at acceptable levels over the 4‐day shelf life because of the combined effects of temperature, acidity, and redox potential. Chill storage slows post‐fermentation acidification and prolongs bifidobacterial viability while packaging materials, which present a greater barrier to oxygen, had a similar effect. The results indicated that bifidobacteria could be successfully incorporated into buffalo curd to give a product which has improved acceptability. Probiotic buffalo curd, when compared to uninoculated curd, had significantly higher (P < 0.05) sensory scores for properties such as taste and mouth‐feel resulting in a significantly higher (P < 0.001) overall acceptability.     

Viability and Resistance of Lactobacilli Isolated from Cocoa Fermentation to Simulated Gastrointestinal Digestive Steps in Soy Yogurt

To study the potential probiotic characteristics such as decrease of pH, microbial viability, and tolerance to simulated digestive steps of fermented soy beverage (“soy yogurt”) produced with lactobacilli isolated from cocoa fermentation (Lactobacillus fermentum TcUESC01 and Lactobacillus plantarum TcUESC02) during fermentation and refrigerated storage. The sensory acceptance of the yogurts was also tested. Samples of soy yogurt produced with L. fermentum TcUESC01 or L. plantarum TcUESC02 were collected during fermentation (0, 4, 8, and 12 h) and refrigerated storage (1, 9, 18, and 27 d), and submitted to pH and bacterial viability determinations. Tolerance to simulated digestion steps was done with refrigerated storage samples at 9 °C. Simulated digestion was performed in 3 successive steps: exposure to pepsin‐HCl solution, bile shock, and simulated small intestinal juice. During storage, a decrease in pH and lactobacillus viability was observed. L. fermentum TcUESC01 showed to be more resistant than L. plantarum TcUESC02 to simulated gastrointestinal digestion. All soy yogurts showed acceptable hedonic scores (greater than 5 in a 9‐point hedonic scale ranging from “like extremely” to “dislike extremely”) in sensory evaluation for flavor, aroma, color, consistency, and overall impression. L. plantarum TcUESC02 and, especially, L. fermentum TcUESC01 showed potential probiotic characteristics when considering pH, cell viability, and tolerance to simulated digestive steps and did not affect the sensory characteristics when supplemented to soy yogurt during storage.     

Survival of Lactobacillus casei and functional characteristics of reduced sugar red beetroot yoghurt with natural sugar substitutes

In this study, probiotic gel fermentation and functional characteristics of reduced sugar yoghurt with red beetroot bioactive components and steviol glycosides from Stevia rebaudiana extracts as natural source of noncaloric sweeteners were investigated. A significant increase in Lactobacillus casei viability and fermented gel network and a decrease in syneresis were determined in yoghurt sweetened with steviol glycosides and high content of red beetroot bioactive components such as total phenolics, anthocyanins and total antioxidant capacity (DPPH and FRAP). The survival of L. casei was maintained within probiotic and therapeutic levels (>9 log₁₀ CFU/g), due to the possible prebiotic effect of steviol glycosides and fermentable fibres and phenolic compounds of red beetroot during 28 days of cold storage of the probiotic yoghurts. Colour properties (L*, a*, b*, ΔE*, C*, h*) and such sensory properties as smoothness, sweetness astringency were significantly affected. The highest organic acid content was found in red beetroot enriched yoghurt with stevia, while the most dominant organic acids were butyric, lactic, malic and citric. As a result, it was determined that fermented milk products, which are supported by phytochemical and steviol glycoside interactions, have adequate nutritional effects, high probiotic viability and acceptable sensory properties     

Effects of a mixed koji culture of Aspergillus oryzae HG‐26 and Aspergillus niger HG‐35 on the levels of enzymes,antioxidants and phenolic compounds in soy sauce during the fermentation process

Soy sauce contains a number of bioactive components, which have been shown to possess strong antioxidative properties. The objective of this study was to compare the enzyme activities, antioxidant activity and phenolic compounds content of soy sauces prepared from a mixed koji (SSAON, inoculated with Aspergillus oryzae HG‐26 and Aspergillus niger HG‐35), with those of soy sauces made from a koji culture containing only Aspergillus oryzae HG‐26 koji (SSAO). The total phenolic content (TPC), total flavonoid content (TFC), content of three isoflavone aglycones (daizein, glycitein and genistein) and the antioxidant activity of the SSAON were found to be higher than those of the SSAO during moromi fermentation. In addition, they showed strong positive correlations with the antioxidant potential of the soy sauce. This study has demonstrated the potential of a mixed‐culture koji, based upon A. orzyae and A. niger, for the production of soy sauce with an increased level of bioactive components.     

Incorporation of Propionibacterium shermanii subsp. freudenreichii in probiotic dairy drink production: physicochemical,rheological, microbiological and sensorial properties

The aim of this study was to investigate the use of Propionibacterium shermanii subsp. freudenreichii as a combined culture with Lactobacillus acidophilus (AP), Bifidobacterium animalis subsp. lactis (BP), Lactobacillus casei (CP) and Lactobacillus rhamnosus (RP) in probiotic dairy drink production. Although Propionibacterium spp. is used for many purposes including biopreservative and adjunct culture, in this study, probiotic dairy drinks containing P. freudenreichii were evaluated in terms of their physicochemical, rheological, microbiological and sensory properties. The results of the study showed that P. freudenreichii can also be suitable for the production of probiotic drinks and that there are no adverse effects on the product characteristics.     

Innovations in Indian Fermented Milk Products — A Review

Dahi is considered the oldest Indian fermented milk product and is equivalent to Western yogurt from which derivatives such as shrikhand (sweetened concentrated curd) and lassi (stirred curd) are derived. Dietetic significance of Indian fermented milk products has been established due to its various nutritional and therapeutic properties. Acceptable quality dahi could be obtained with the application of acid producing as well as flavor (primarily diacetyl)-producing organisms and adopting a two-stage fermentation. Biotechnological innovations suggest inclusion of certain probiotic and beneficial bacteria for further enhancement in the dietetic properties of traditional dahi. Application of bio-preservatives and thermization (mild heat-treatment) may be recommended for shelf-life extension of dahi to extend the market reach.     

Survival,growth characteristics and bioactive potential of Lactobacillus acidophilus in a soy‐based cream cheese

BACKGROUND: Soy‐based products have received much attention lately as dairy replacers and carriers for probiotics, without the cholesterol and lactose intolerance factors. We have previously developed a soy cream cheese product and would like to evaluate its suitability as a carrier for probiotic microorganisms. Soy cream cheese is commercially uncommon, while a probiotic soy cream cheese is yet to be available in the market. RESULTS: Five strains of probiotics were screened for their α‐galactosidase activity. Lactobacillus acidophilus FTCC 0291 showed the highest α‐galactosidase‐specific activity and was incorporated into soy cream cheese for a storage study of 20 days at 25 and 4 °C. L. acidophilus FTCC 0291 in soy cream cheese at both storage temperatures maintained a viability exceeding 10⁷ CFU g^?1 over storage. Oligosaccharide and reducing sugar analyses indicated that L. acidophilus FTCC 0291 was capable of utilizing the existing reducing sugars in soymilk and concurrently hydrolyzing the oligosaccharides into simpler sugars for growth. L. acidophilus FTCC 0291 also produced organic acids, leading to decreased pH. Under low pH and high organic acid concentration, the growth of total aerobes and anaerobes was significantly (P < 0.05) suppressed compared to the control. The hydrolysis of protein in soymilk produced essential growth factors such as peptides and amino acids that may have promoted the growth of L. acidophilus FTCC 0291 and the release of bioactive peptides with in vitro angiotensin I‐converting enzyme inhibitory activity. CONCLUSION: This study showed that soy cream cheese could be used as a carrier for probiotic bacteria, with potential antihypertensive property. Copyright © 2009 Society of Chemical Industry     

Promoting Lactobacillus casei and Bifidobacterium adolescentis survival by microencapsulation with different starches and chitosan and poly L‐lysine coatings in ice cream

In this research, microencapsulation of the probiotics Lactobacillus casei ATCC 39392 and Bifidobacterium adolescentis ATCC 15703 was performed using calcium alginate, wheat, rice, and high‐amylose corn (Hylon VII) starches along with chitosan and poly L‐lysine coatings. The effect of microencapsulation on the survival and sensory properties of ice cream over 100 days at ?30 °C was evaluated. Scanning electron and optical microscopy were employed to measure capsule size and morphology. The results suggested that the survival of probiotics is increased by microencapsulation. Coating the capsules with chitosan and poly L‐lysine led to enhanced bacterial viability and an increase in the size of microcapsules. Among different starches, Hylon starch enhanced the survival of probiotics at low temperatures the most. Furthermore, the addition of probiotics in free and encapsulated states did not have a significant effect on the sensory properties, or pH levels of the final product during storage (p > .05).

Practical applications

Microencapsulation using various hydrocolloids is a commonly used method for enhancing probiotic survival in ice cream during the frozen storage. This study indicates that the microencapsulation of probiotics can enhance probiotic survival in ice cream after 100 days of storage at ?30 °C. Chitosan and poly L‐lysine coatings significantly improved the survival of encapsulated probiotics during the storage of ice cream. This improvement is attributed to the role of Hylon starch in creating more integrated microcapsule structure. Moreover, sensory evaluation of ice cream revealed that inoculation with the probiotic culture, in either the encapsulated or the free‐state, had no significant effect on texture, color, flavor, taste, or general sensory characterization of ice cream during the storage period at ?30 °C (p > .05).     

Production of functional probiotic, prebiotic, and synbiotic ice creams

In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.     

Influence of dietary supplementation with Bacillus-fermented adlay on lipid metabolism, antioxidant status and intestinal microflora in hamsters

BACKGROUND: The effects of polished and dehulled Bacillus‐fermented adlay on lipid metabolism, antioxidant status and intestinal microflora were examined in hyperlipidaemic hamsters fed a high‐cholesterol diet. RESULTS: Hamsters administered Bacillus‐fermented adlay experienced significantly reduced (P < 0.05) serum and hepatic total cholesterol (by 37–43% and 42–49% respectively) and triglyceride (by 22–27% and 30–35% respectively) levels compared with the high‐cholesterol group. Lower low‐density lipoprotein cholesterol/high‐density lipoprotein cholesterol ratios in serum and increased cholesterol (by 47–52%) and triglyceride (by 40–47%) contents in faeces were also observed. Bacillus‐fermented adlay lowered the levels of thiobarbituric acid‐reactive substances, thus increasing total antioxidant and superoxide dismutase activities. In particular, polished Bacillus‐fermented adlay had satisfactory antioxidant activity, similar to that of commercially available natto. Moreover, hamsters fed Bacillus‐fermented adlay harboured greater populations of lactic acid bacteria, few coliforms and little Clostridium perfringens. CONCLUSION: This study has shown that changes in lipid metabolism, antioxidant status and intestinal microflora can be greatly modulated by Bacillus‐fermented adlay, suggesting potential novel approaches to the treatment of primary cardiovascular and intestinal diseases. Copyright © 2011 Society of Chemical Industry     

Comparison of microbial communities between normal and swollen canned soy sauces using nested PCR‐denaturing gradient gel electrophoresis,HPLC and plate techniques

The microbial community of normal and swollen canned soy sauce was investigated using molecular biological method. The PCR‐denaturing gradient gel electrophoresis (DGGE) profiles showed that four lactic acid bacteria (LAB), including Lactobacillus acidipiscis, L. pobuzihii, L. piscium and another Lactobacillus sp., were involved in the swollen canned samples. Plate technique showed that three diverse species of Bacillus (B. subtilis, B. oleronius and B. flexus) were present in the swollen canned samples. However, much less bacterial contaminants were detected in the normal samples. According to the HPLC analysis, the lactic acid concentrations of the swollen canned samples were significantly higher than those in the normal samples. These results indicated that LAB can play a key role in contributing to the acidisation of the swollen canned soy sauce products. Our results confirmed the existence of Bacillus sp. and LAB in the packaged fermented soy sauce.     

Probiotic Strains as Starter Cultures Improve Angiotensin-converting Enzyme Inhibitory Activity in Soy Yogurt

Suitability of soy yogurt as a system for delivering probiotics and other bioactive compounds was assessed by fermenting soy milk using starter culture containing Lactobacillus delbrueckii ssp. bulgaricus Lb1466, Streptococcus thermophilus St1342, and probiotic organisms (Lactobacillus acidophilus LAFTI® L10, Bifidobacterium lactis LAFTI® B94, and Lactobacillus paracasei LAFTI® L26). Fermentations were terminated at different pH of 4.50, 4.55, and 4.60 and metabolic patterns of cultures (viability, proteolytic activity, organic acids production, angiotensin‐converting enzyme (ACE) inhibitory activity) were investigated during 28 d of storage at 4 °C. The presence of probiotics enhanced the growth of L. delbrueckii ssp. bulgaricus Lb1466 and S. thermophilus St134 in soy yogurt in comparison to the control produced by sole yogurt culture. In general, different termination pH had no effect (P > 0.05) on the viability of probiotic organisms that maintained good viability in soy yogurt during cold storage. Higher levels of essential growth factors in the form of peptides and amino acids in soy yogurts may have promoted the growth of L. acidophilus LAFTI® L10, B. lactis LAFTI® B94, and L. paracasei LAFTI® L26. The use of probiotic strains as a part of starter culture in soy yogurt resulted in a substantial increase in in vitro ACE inhibitory activity compared with the control produced by yogurt culture only. This improvement of ACE inhibition in soy yogurt is partly due to higher proteolytic activity of probiotics.     

Storage Stability and Acceptance of Probiotic Beverage from Cashew Apple Juice

The stability of nonfermented cashew apple juice (control) and the fermented juice with Lactobacillus casei NRRL B-442 (sweetened and nonsweetened samples) was investigated along the storage at 4 °C for 42 days. The viability of the probiotic bacteria, sugars, lactic acid, and vitamin C content besides color, antioxidant activity, enzyme activity, and sensory characteristics of probiotic cashew apple juice was evaluated. It was observed that viable cell counts increased in the probiotic cashew apple containing sucrose (8 % w/v) along the storage period. Viable cell counts were always higher than 8.00 Log CFU/ml throughout the storage period. Ascorbic acid loss was higher in the nonfermented juice (40 %) compared to the fermented juice (23 %). The same behavior was observed for antioxidant activity and total polyphenolic compounds content, conferring nutritional benefits to this functional food. Browning reactions and nutritional breakdown caused by enzymes were minimized in the fermented samples during storage. In the fermented sample, higher reduction (>70 %) in the polyphenol oxidase enzyme activity was observed. During storage, the increase in the chroma values from 3.2 to 5.0 indicated that the yellow color became more vivid. Sensory analysis of the fermented cashew apple juice revealed that the product was well-accepted, with acceptance percentages above 80 % for the sweetened juice at the end of the storage period.     

High-intensity ultrasound reduces fermentation time and improves textural properties,antioxidant activity and probiotic survival in fermented probiotic strawberry drink

This study aimed to evaluate the effect of high-intensity ultrasound (HIUS) application with different processing times (2.5, 5, 7.5 and 10 min) on the physicochemical, rheological and textural properties, antioxidant activity (AA) and probiotic survival in strawberry-flavoured fermented probiotic strawberry drink during storage (7°C for 28 days). The application of HIUS resulted in products with lower fermentation times, higher organic acid stability during storage and improved texture (higher firmness and consistency) and functional properties (higher phenolic compounds content and/or AA). Using 2.5 min of processing time would be advisable due to the better probiotic survival to simulated gastrointestinal conditions (probiotic counts higher than 10⁶ CFU mL⁻¹), reduced fermentation times (reduction in 3 h), higher lactic acid content during storage and enhanced AA. The products showed a viable probiotic counts higher than 10⁶ CFU mL⁻¹ during the entire shelf life. HIUS may be considered as an adequate pre-treatment in the development of probiotic fermented probiotic strawberry drink.     

Development of extruded snacks using soy,sorghum, millet and rice blend – A response surface methodology approach

Response surface methodology (RSM) based on a five‐level‐three‐factor central composite rotatable design (CCRD) was employed for optimisation of formulation for production of a soy‐fortified millet‐based extruded snack. Effects of amount of ingredients such as ragi (40–50%), sorghum (10–20%) and soy (5–15%) on the physical properties like bulk density, expansion ratio, water absorption index and water solubility index of snacks were investigated. Significant regression models that explained the effects of different percentages of ragi, sorghum and soy on all response variables were determined. The coefficients of determination, R², of all the response variables were higher than 0.90. Based on the given criteria for optimisation, the basic formulation for production of millet‐based extruded snack with desired sensory quality was obtained by incorporating with 42.03% ragi, 14.95% sorghum, 12.97% soy and 30% rice.     

PHENOLIC ANTIOXIDANT ENRICHMENT OF SOY FLOUR-SUPPLEMENTED GUAVA WASTE BY RHIZOPUS OLIGOSPORUS-MEDIATED SOLID-STATE BIOPROCESSING

In this paper, we investigated the potential for Rhizopus oligosporus to produce enhanced levels of free phenolics from guava residue mixed with soy flour as the nitrogen source.β‐glucosidase activity and antioxidant activity in crude extracts were evaluated. Two substrates were studied based on carbon and nitrogen ratios: A, 90% guava residue : 10% soy flour (G9) and B, 50% guava residue : 50% soy flour (G5). Bioprocessing increased water extractable phenolics 12.9% with G9 substrate and 98.6% with G5 substrate. For both substrates, antioxidant activity increased during early stages of fungal growth but decreased thereafter. Phenolic antioxidant mobilization during bioprocessing was associated withβ‐glucosidase activity and hypothesized to involve the mobilization of polymeric phenolics. The bioconversion of soy flour‐supplemented guava residue by R. oligosporus represents a novel strategy for the enhancement of phenolic antioxidant content and potential commercial value of guava wastes.     

In vitro probiotic evaluation of potential antioxidant lactic acid bacteria isolated from idli batter fermented with Piper betle leaves

Lactic acid bacteria isolated from food sources can be introduced as probiotics because of their health‐promoting and nonpathogenic characteristics. Eight lactic acid bacteria from idli batter fermented with Piper betle leaves were selected to screen the antioxidant potential and biofilm‐forming ability. Five isolates exhibited good antioxidant potential and biofilm formation and showed antagonistic activity against the pathogenic biofilm‐forming Staphylococcus aureus. Further, in vitro probiotic properties of five isolates exhibited excellent acid tolerance, bile tolerance, simulated gastrointestinal juice tolerance, auto‐aggregation and co‐aggregation and hydrophobicity and showed resistance to antibiotics such as ciprofloxacin, nalidixic acid, norfloxacin and colistin. Isolates also showed positive bile salt hydrolase activity, cholesterol assimilation, β‐galactosidase production and mucin binding ability. The isolate KJBB10 exhibited good adhesion and pathogen exclusion percentage with human colon cancer cells (HCT‐15 and HT‐29). Hence, the isolates KJBB10, KJBB56 and KJBC06 can be used as beneficial probiotic starter cultures for the formulation of functional foods.     

Evaluation of total phenol content and antioxidant properties of encapsulated grape seed extract in yoghurt

The effect of encapsulated (En) and nonencapsulated (NE) grape seed extract (GSE) at 1% level added to milk before its fermentation was evaluated on the physicochemical properties, total phenolic content and antioxidant activity of the resulting yoghurt. Encapsulated GSE resulted in a product comparable to the control, based on sensory properties, acidity, water‐holding capacity, viscosity and colour, along with a threefold increase in total phenolic content and fourfold increase in antioxidant activity. The GSE addition resulted in no effect on the viability of Streptococcus thermophilus and Lactobacillus bulgaricus subsp. delbrueckii counts. The product with NE‐GSE had poor sensory properties and lesser polyphenol stability during storage as compared to En‐GSE yoghurt.     

Simultaneous effects of gelatin and espina corona gum on rheological,physical and sensory properties of cholesterol‐reduced probiotic yoghurts

The effects of gelatin (G) and espina corona gum (ECG) on rheological, physical and sensory properties of cholesterol‐reduced probiotic yoghurts were studied. The results showed that it was possible to efficiently remove the cholesterol (> 85%) and the probiotic microorganism counts were > 7 log₁₀ CFU.g^?1. The addition of G decreased flow behaviour index (n), while consistency index (K) increased with the addition of both thickeners. Thixotropy, initial shear stress of the clot to be deformed by mechanical action (A) and destruction rate of the structure (B) were enhanced by increasing G. ECG imparted greater creaminess, less grittiness and less astringency, while G gave more consistency. Both hydrocolloids helped to reduce acid taste and increased water retention index (> 95%). The optimum formulations were: 0.49% G – 0.41% ECG to obtain set yoghurts and 0.01% G – 0.43% ECG for stirred yoghurts, with desirable sensory, rheological and stability characteristics.