Abstract: The consumption of functional foods is very common. For this reason, many products which are probiotic, prebiotic, energy reduced and fat reduced are developed. In this research, physicochemical and microbiological properties of functional kefir, kefir yogurt and chickpea yogurt were examined. For this purpose, pH values, titration acidities, viscosity values, water holding capacities, serum separation values, acetaldehyde contents, tyrosine contents, the count of aerobic mesophilic bacteria, lactic acid bacteria count and mold-yeast counts were determined. As a result of performed analysis, the differences between titration acidities, serum separation values, water holding capacities, acetaldehyde and tyrosine contents of samples were statistically significant (p < 0.05). There were no significant differences on pH values, viscosities, and microbiological properties of samples (p > 0.05). Consequently industrial production of functional kefir yogurt and chickpea yogurt may be advised.
Abstract: Goat dairy products are gaining popularity worldwide. In developing countries, but also in many marginal regions of the Mediterranean area, goats represent a great part of the economy and ensure food security. In fact, these small ruminants are able to convert efficiently poor weedy plants and small trees into traditional products of high nutritional quality, showing great resilience to different climatic and environmental conditions. In developed countries, goat milk is appreciated for the presence of health-promoting compounds, bioactive compounds such as conjugated linoleic acids, oligosaccharides, sphingolipids and polyammines. This paper focuses on the recent advances in literature on the nutritional properties of goat milk and on innovative techniques to improve its quality as to become a promising functional food. The environmental sustainability of different methodologies of production has also been examined. Goat milk is valued today as a food of high nutritional value and functional properties as well as small environmental footprint. It is widely consumed in many countries due to high nutritional value, lower allergenic potential, and better digestibility when compared to bovine milk, that makes this product suitable for infants, elderly or sensitive patients. The main differences in chemical composition between a cow and goat milk rely on fat globules that in goat milk are smaller and in fatty acids that present a smaller chain length, while protein, fat, and lactose concentration are comparable. Milk nutritional properties have demonstrated to be strongly influenced by animal diet, genotype, and welfare, but also by season and production systems. Furthermore, there is a growing interest in the dairy industry in goat milk for its relatively high concentration of prebiotics and a good amount of probiotics, which have recently gained importance for their therapeutic potential. Therefore, goat milk is studied as a promising matrix to develop innovative functional foods. In addition to the economic and nutritional value, goat milk is considered a sustainable product for its small environmental footprint, as they require relatively little water and land, and less medical treatments, compared to cow, these characteristics make its production naturally vocated to organic farming. Organic goat milk production has becoming more and more interesting both for farmers and consumers as it can answer to several concerns like environment protection, animal welfare and economical sustainment of rural populations living in marginal lands. These evidences make goat milk an ancient food with novel properties and advantages to be valorized and exploited.
Abstract: The β-glucan produced by Ophiocordyceps dipterigena BCC 2073 is a (1, 3)-β-D-glucan with highly branching O-6-linkedside chains that is resistant to acid hydrolysis (by hydrochloric acid and porcine pancreatic alpha-amylase). This β-glucan can be utilized as a prebiotic due to its advantageous structural and biological properties. The effects of using this β-glucan as the sole carbon source for the in vitro growth of two probiotic bacteria (L. acidophilus BCC 13938 and B. animalis ATCC 25527) were investigated. Compared with the effect of using 1% glucose or fructo-oligosaccharide (FOS) as the sole carbon source, using 1% β-glucan for this purpose showed that this prebiotic supported and stimulated the growth of both types of probiotic bacteria and induced them to produce the highest levels of metabolites during their growth. The highest levels of lactic and acetic acid, 10.04 g·L-1 and 2.82 g·L-1, respectively, were observed at 2 h of cultivation using glucose as the sole carbon source. Furthermore, the fermentation broth obtained using 1% β-glucan as the sole carbon source had greater antibacterial activity against selected pathogenic bacteria (B. subtilis TISTR 008, E. coli TISTR 780, and S. typhimurium TISTR 292) than did the broths prepared using glucose or FOS as the sole carbon source. The fermentation broth obtained by growing L. acidophilus BCC 13938 in the presence of β-glucan inhibited the growth of B. subtilis TISTR 008 by more than 70% and inhibited the growth of both S. typhimurium TISTR 292 and E. coli TISTR 780 by more than 90%. In conclusion, O. dipterigena BCC 2073 is a potential source of a β-glucan prebiotic that could be used for commercial production in the near future.
Abstract: In recent years, the consumption of functional foods, including foods containing probiotic bacteria, has come to notice. Milk proteins have been identified as a source of angiotensin-I-converting enzyme )ACE( inhibitory peptides and are currently the best-known class of bioactive peptides. In this study, the effects of adding prebiotic ingredients (inulin and wheat fiber) and fat percentage (0%, 2% and 3.5%) in yogurt containing probiotic Lactobacillus casei on physicochemical properties, degree of proteolysis, antioxidant and ACE-inhibitory activity within 21 days of storage at 5 ± 1 °C were evaluated. The results of statistical analysis showed that the application of prebiotic compounds led to a significant increase in water holding capacity, proteolysis and ACE-inhibitory of samples. The degree of proteolysis in yogurt increases as storage time elapses (P < 0.05) but when proteolysis exceeds a certain threshold, this trend begins to decline. Also, during storage time, water holding capacity reduced initially but increased thereafter. Moreover, based on our findings, the survival of Lactobacillus casei in samples treated with inulin and wheat fiber increased significantly in comparison to the control sample (P < 0.05) whereas the effect of fat percentage on the survival of probiotic bacteria was not significant (P = 0.095). Furthermore, the effect of prebiotic ingredients and the presence of probiotic cultures on the antioxidant activity of samples was significant (P < 0.05).
Abstract: Enzymes are the biocatalysts which catalyze the biochemical processes and thus have a wide variety of applications in the industrial sector. β-Galactosidase (E.C. 3.2.1.23) also known as lactase, is one of the prime enzymes, which has significant potential in the dairy and food processing industries. It has the capability to catalyze both the hydrolytic reaction for the production of lactose hydrolyzed milk and transgalactosylation reaction for the synthesis of prebiotics such as lactulose and galactooligosaccharides. These prebiotics have various nutritional and technological benefits. Although, the enzyme is naturally present in almonds, peaches, apricots and other variety of fruits and animals, the extraction of enzyme from these sources increases the cost of enzyme. Therefore, focus has been shifted towards the production of low cost enzyme from the microorganisms such as bacteria, yeast and fungi. As compared to yeast and bacteria, fungal β-galactosidase is generally preferred as being extracellular and thermostable in nature. Keeping the above in view, the present study was carried out for the isolation of the β-galactosidase producing fungal strain from the food as well as the agricultural wastes. A total of more than 100 fungal cultures were examined for their potential in enzyme production. All the fungal strains were screened using X-gal and IPTG as inducers in the modified Czapek Dox Agar medium. Among the various isolated fungal strains, the strain exhibiting the highest enzyme activity was chosen for further phenotypic and genotypic characterization. The strain was identified as Rhizomucor pusillus on the basis of 5.8s RNA gene sequencing data.
Abstract: In order to investigate the prebiotic potential of
oligosaccharides prepared by chemical hydrolysis of water-soluble
polysaccharides (WSP) from Zizyphus lotus leaves, the effect of
oligosaccharides on bacterial growth was studied. The chemical
composition of WSP was evaluated by colorimetric assays revealed
the average values: 7.05±0.73% proteins and 86.21±0.74%
carbohydrates, among them 64.81±0.42% is neutral sugar and the rest
16.25±1.62% is uronic acids. The characterization of
monosaccharides was determined by high performance anion
exchange chromatography with pulsed amperometric detection
(HPAEC-PAD) was found to be composed of galactose (23.95%),
glucose (21.30%), rhamnose (20.28%), arabinose (9.55%), and
glucuronic acid (22.95%). The effects of oligosaccharides on the
growth of lactic acid bacteria were compared with those of fructooligosaccharide
(RP95). The oligosaccharides concentration was
1g/L of Man, Rogosa, Sharpe broth. Bacterial growth was assessed
during 2, 4.5, 6.5, 9, 12, 16 and 24 h by measuring the optical density
of the cultures at 600 nm (OD600) and pH values. During
fermentation, pH in broth cultures decreased from 6.7 to 5.87±0.15.
The enumeration of lactic acid bacteria indicated that
oligosaccharides led to a significant increase in bacteria (P≤0.05)
compared to the control. The fermentative metabolism appeared to be
faster on RP95 than on oligosaccharides from Zizyphus lotus leaves.
Both RP95 and oligosaccharides showed clear prebiotic effects, but
had differences in fermentation kinetics because of to the different
degree of polymerization. This study shows the prebiotic
effectiveness of oligosaccharides, and provides proof for the selection
of leaves of Zizyphus lotus for use as functional food ingredients.
Abstract: Fructo-oligosaccharides (FOS) are produced from
sucrose by Aureobasidium pullulans in yields between 40-60%
(w/w). To increase the amount of FOS it is necessary to remove the
small, non-prebiotic sugars, present. Two methods for producing
high-purity FOS have been developed: the use of microorganisms
able to consume small saccharides; and the use of continuous
chromatography to separate sugars: simulated moving bed (SMB). It
is herein proposed the combination of both methods. The aim of this
study is to optimize the composition of the fermentative broth (in
terms of salts and sugars) that will be further purified by SMB. A
yield of 0.63 gFOS.gSucrose^-1 was obtained with A. pullulans using low
amounts of salts in the initial fermentative broth. By removing the
small sugars, Saccharomyces cerevisiae and Zymomonas mobilis
increased the percentage of FOS from around 56.0% to 83% (w/w) in
average, losing only 10% (w/w) of FOS during the recovery process.
Abstract: The influence of lactulose and inulin on rheological
properties of fermented milk during storage was studied.Pasteurized
milk, freeze-dried starter culture Bb-12 (Bifidobacterium lactis, Chr.
Hansen, Denmark), inulin – RAFTILINE®HP (ORAFI, Belgium) and
syrup of lactulose (Duphalac®, the Netherlands) were used for
experiments. The fermentation process was realized at 37 oC for 16
hours and the storage of products was provided at 4 oC for 7 days.
Measurements were carried out by BROOKFIELD standard methods
and the flow curves were described by Herschel-Bulkley model.
The results of dispersion analysis have shown that both the
concentration of prebiotics (p=0.04
Abstract: Fructooligosaccharides derived from microbial enzyme especially from fungal sources has been received particular attention due to its beneficial effects as prebiotics and mass production. However, fungal fermentation is always cumbersome due to its broth rheology problem that will eventually affect the production of FOS. This study investigated the efficiency of immobilized cell system using rotating fibrous bed bioreactor (RFBB) in producing fructooligosaccharides (FOS). A comparative picture with respect to conventional stirred tank bioreactor (CSTB) and RFBB has been presented. To demonstrate the effect of agitation intensity and aeration rate, a laboratory-scale bioreactor 2.5 L was operated in three phases (high, medium, low) for 48 hours. Agitation speed has a great influence on P. simplicissimum fermentation for FOS production, where the volumetric FOS productivity using RFBB is increased with almost 4 fold compared to the FOS productivity in CSTB that only 0.319 g/L/h. Rate of FOS production increased up to 1.2 fold when immobilized cells system was employed at aeration rate similar to the freely suspended cells at 2.0 vvm.