The Roles of Candida tropicalis Toward Peptide and Amino Acid Changes in Cheese Whey Fermentation (original) (raw)
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Submerged Yeast Fermentation of Cheese Whey for Protein Production and Nutritional Profile Analysis
2011
In this study, ten whey samples collected from dairy industries in Rasht (Iran). Five lactose fermentative yeasts strains (designated A1 to A5) were isolated. Beta-galactosidase activity in the yeast strains showed that strain of Kluyveromyces marxianus designated as A2 had highest enzyme activity (up to 9012 EU/mL) and the most SCP production from whey with the yield of 12.68 g/L. Ammonium sulfate as nitrogen source had an increasing effect on biomass yield up to 30%. Crude fiber, lipids, carbohydrates and ash content of isolate dry cells were found to be 4.9, 7.23, 33.19 and 14.05%, respectively. The true protein content based on nitrogen fractionation procedure was 29.25%. The yeast biomass recovering by ultrafiltration reduced the total COD to 96.26% of its initial value in the raw whey.
Bioactivity of probiotic whey cheese: characterization of the content of peptides and organic acids
Journal of the Science of Food and Agriculture, 2013
BACKGROUND: Probiotic whey cheeses have been produced for several years. It is recognized that several bacterium-mediated metabolic activities contribute differently to the final sensory and nutritional profiles of dairy products. Hence the metabolic activity of probiotic strains in a whey cheese and their contribution to the bioactivity of such matrices were investigated here, including in particular Bifidobacterium animalis, Lactobacillus acidophilus and Lactobacillus casei. RESULTS: Both L. casei and B. animalis produce lactic and acetic acids, whereas L. acidophilus produce mainly lactic acid; these metabolites may be considered bioprotection factors. Water-soluble extracts (WSE) obtained from these cheese matrices were subjected to ultrafiltration through a 3 kDa cutoff membrane, and the eluted peptides were resolved by high-performance liquid chromatography. Different qualitative and quantitative profiles were obtained, depending on the strain. WSE were further assayed for their ability to inhibit angiotensin-converting enzyme; the <3 kDa fraction exhibited higher activities in the case of L. casei and B. animalis than the control and L. acidophilus. CONCLUSION: Whey cheeses with higher nutritional value were those inoculated with L. casei.
International Journal of Food Science & Technology, 2017
Novel bacterial (HT) and fungal (FPII) food-grade protease preparations were evaluated for their ability to hydrolyse sheep cheese whey (SCW) and the generation of bioactive peptides. Both protease preparations hydrolysed the whey proteins to small peptides over 24-h hydrolysis time, but the time course hydrolysis profiles were different as evaluated by SDS-PAGE. The HT whey hydrolysate had considerably higher antioxidant and angiotensin-I converting enzyme (ACE)-inhibitor activity than the FPII hydrolysate. Neither hydrolysate was cytotoxic towards Vero cells. OFFGEL electrophoresis of the small peptide pool fraction (<15 amino acids) of each hydrolysate indicated differences in the pI distribution of the bioactive peptides. This likely reflects the diverse hydrolytic specificity of the proteases. Although the antioxidant activity of both hydrolysates was not significantly affected by simulated gastrointestinal digestion, the loss of ACE-inhibitor activity was greater with the FPII hydrolysate.
Food Research International, 2011
Hard cooked cheeses are mostly manufactured with lactic starters of Lactobacillus helveticus, which constitute a major proteolytic agent in the food. In this work, we assessed the proteolysis produced by enzymes of two strains of L. helveticus in a new cheese model, which consisted of a sterile substrate prepared with hardcooked cheeses, and identified the time of ripening when main changes in proteolysis are produced. The extract, a representative model of the aqueous phase of the cheeses, was obtained from Reggianito cheeses of different ripening times (3, 90, and 180 days) made with starters composed of the strains tested, either SF138 or SF209. To obtain the substrate, the cheese was extracted with water, then centrifuged and the aqueous phase was sterilized by filtration through membrane (0.45 μm). The substrates were incubated at 34°C during 21 days; samples were taken at 0, 3, 7, 14, and 21 days. Sterility was verified by plating samples on skim milk agar and incubating at 37°C for 48 h. Proteolysis was determined by liquid chromatography of soluble peptides and free amino acids. Great variation in peptide profiles was found as incubation progressed in cheese extracts, which evidenced that proteases and peptidases from the starter were active and able to degrade the proteinaceous material available in the extracts. The extracts derived from cheeses with L. helveticus SF138 showed low production of peptides and a notable increase in free amino acids content during incubation. L. helveticus SF209, on the contrary, caused an increase on soluble peptides, but the free amino acids accumulation was lower than in the first case, which suggested that L. helveticus SF209 had either a low peptydolitic activity or produced an intense amino acids breakdown. This trend was more evident for extracts prepared with 90-day-old cheeses. It was concluded that the strains of L. helveticus assayed showed potentially complementary proteolytic abilities, as SF209 was able to provide a continuous replenishment of peptides during incubation, while SF138 increased their hydrolysis to free amino acids. The extract was an appropriate medium to model hard cooked cheese ripening in short periods of time.
Cheese flavour development by enzymatic conversions of peptides and amino acids
Food Research International, 2000
During ripening of cheese, many biochemical processes take place, which are essential for¯avour development. The breakdown of caseins is a prerequisite for¯avour development. A good balance between proteolysis and peptidolysis prevents the formation of bitterness in the cheese. For this reason, it is necessary to focus on starter cultures with highly active peptidases, which should be active in the cheese matrix. Amino-acid-converting enzymes (AACEs) are involved in the degradation of amino acids, which are liberated during proteolysis. Their activity results in various volatile (¯avour) components; most notably the degradation of methionine results in¯avour-active sulphur compounds. AACEs involved in degradation of methionine and other amino acids were identi®ed and their role in (cheese)¯avour formation is described. At least two pathways leading to the formation of sulphur compounds were identi®ed. Overproduction of one of the enzymes involved, results speci®cally in a higher formation of sulphur compounds. This result, together with the observation that¯avour production is highly strain-speci®c amongst various lactococcal bacteria, oers a new potential for industrial applications.
Food Research International, 2017
Canastra cheese is a cheese with geographical indication recognized by the Brazilian National Institute of Industrial Protection under number IG201002. It is produced in seven municipalities in the state of Minas Gerais in a region called Serra da Canastra. In this work, samples of milk, "pingo" (natural starter), whey and Canastra cheese were collected on a farm in Medeiros-MG/Brazil to evaluate the yeast microbiota and select yeasts for whey fermentation to produce ethanol and volatile aromatic compounds of relevance in the production of cheese. Thirtynine isolates capable of fermenting lactose in a synthetic medium were identified by MALDI-TOF as Kluyveromyces lactis (29), Torulaspora delbrueckii (7) and Candida intermedia (3). Eleven isolates of K. lactis and three of T. delbrueckii efficiently fermented lactose until 4th day, and due to this reason were selected for cheese whey fermentation with Brix 12, 14 and 18. Generally, the isolates T. delbrueckii B14, B35, and B20 and K. lactis B10 were the most effective regardless of the initial Brix value. The identification of these four isolates by MALDI TOF was confirmed by sequencing of the ITS region. In the fermentation of cheese whey 14 Brix, T. delbrueckii B14 and B35, respectively yielded 24.06 g/L and 16.45 g/L of ethanol, while K. lactis B10 was more efficient in the consumption of lactose. In sequential culture with K. lactis B10 inoculated 48 h after T. delbrueckii B14, 97.82% of the total sugars were consumed resulting in the production of 19.81 g/L ethanol and 39 aromatic volatile compounds. The most abundant compounds were 3-methyl-1-butanol, octanoic acid and ethyl decanoate, which are reported as important for the aroma and flavor of cheeses. Based in our results, B10 isolate inoculated 48 h after B14 isolate is a promising yeast inoculum to be used for fermentation of dairy substrates.
Prilozi - Makedonska akdemija na naukite i umetnostite. Oddelenie za prirodno-matematički i biotehnički nauki, 2019
After the cheese production process, the whey, obtained as a by-product, is not valorised and remains in the waste water which is usually disposed of in natural watercourses. The aim of the study was to analyse the profile of whey proteins, as well as, to quantify the amount of those fractions. 12.5 % SDS-PAGE was used. The total amount of proteins in whey from cow white cheese was 0.73 % ± 0.15, while in cow kashkaval whey was 0.91 % ± 0.08. In whey from white cheese, the relative protein percentages were: lactoglobulin 67.29 % ± 4.99, lactalbumin 20.64 % ± 2.02 and other fractions related to bovine serum albumin with 12.07 % ± 3.05. In whey from yellow cheese, the proteins percentages were: lactoglobulin 52.62 % ± 1.21, lactalbumin 17.62 % ± 1.26 and other fractions related to bovine serum albumin with 29.74 %, respectively. Predominantly, -lactoglobulin was present in the analysed samples. The valorisation of the waste whey obtained in the white cheese production, and development of new product also contributes in the environment protection.
Biotechnology & Biotechnological Equipment, 2014
Some lactic acid bacteria strains in milk media are capable of releasing bioactive peptides. In this study, we evaluated the angiotensin-converting enzyme (ACE)inhibitory activity of 180 lactic acid bacteria and selected several Lactobacillus helveticus, L. delbrueckii subsp. bulgaricus and L. casei strains that demonstrated strong ACE-inhibitory activity. The aim was to carry out a molecular study on the bioactive peptides released by the strains with the best ACE-inhibitory properties and by the strains demonstrating a calcium-binding effect. To the best of our knowledge, this is the first study of bioactive peptides in Bulgarian white cheese. Peptides with the strongest ACE-inhibitory activity were purified and sequenced. The strains were assessed for production of peptides with calcium-binding properties. These peptides were isolated, purified and sequenced. Two strains releasing bioactive peptides with the strongest ACE-inhibitory and calcium-binding activities were selected for development of cheese starters. The strain with the best ACE-inhibitory activity was L. helveticus A1, which releases the peptide Ala-Leu-Pro-Met as a main contributor to the ACE inhibition. The strain with the best calcium-binding activity was L. casei C3 releasing the peptide SpLSpSpSpE (fraction 15À20 of ß-casein) as a main contributor to calcium binding. After pilot production of cheeses with the developed starters, the ACE-inhibitory and calcium-binding effects were confirmed during the cheese ripening. The addition of the two selected adjunct cultures led to increased production of bioactive peptides in the cheese. In this way, it is possible to increase the functional properties of Bulgarian white brined cheese.
Role of using adjunct cultures in release of bioactive peptides in white-brined goat-milk cheese
LWT, 2020
A mixed commercial starter culture containing Lactococcus lactis subps lactis and Lactococcus lactis subsp cremoris (Cheese A, control) was combined with three adjunct cultures including Lactobacillus casei (Cheese B), Lactobacillus plantarum (Cheese C) and Lactobacillus bulgaricus (Cheese D) in the manufacture of white brined cheese using goat's milk. Use of adjunct culture was not significantly affected pH and gross chemical composition except for nitrogenous compounds; however, use of adjunct cultures in cheese manufacture showed a potential increase in ACE-inhibitory and antioxidant activity parallel to the increase in water-soluble nitrogenous compounds until the 60th day of ripening. The highest antioxidant and ACE-inhibitory activity was detected in cheese D (62.55%) and cheese B (51.95%), respectively. All cheese samples showed almost similar peptide profile; however, quantitative differences were observed. In conclusion, use of adjunct cultures in white-brined goat-milk cheese manufacturing contribute to increase in ACE-inhibitory activity and antioxidant activity.