Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this research was to study the effects of dairy maturation on the physico-chemical characteristics and technological properties of milk used for Parmigiano-Reggiano cheese manufacture. Three different operating conditions (CF1, CF2 and CF3) were considered. Full cream milk from the evening milking was stored on the farm and delivered to the cheese factory in churns (CF1) or in thermoregulated tanks at a temperature not lower than 18 degrees C (CF2 and CF3). The natural creaming (10-12 h overnight) was performed in a traditional large flat vat containing 10-12 hl (CF1 and CF2) or in thermoregulated large flat vats containing 60 hl at about 15 degrees C (CF3). Twenty-four, 24 and 22 maturation trials were performed in CF1, CF2, and CF3, respectively, during 2 consecutive years. A significant increase (P<or=0.05) in pH during the maturation of milk was observed in CF1 and CF2. The increase of pH was higher (P<or=0.05) in CF1 than CF2 and CF3. The values of titratable acidity were higher (P<or=0.05) in partially skimmed evening (PS) milk than in full cream (FC) milk in each operative condition. The increase observed in CF2 was higher than those reported in CF1 and CF3. Compared with FC milk, PS milk showed lower values (P<or=0.05) of casein and casein number and higher contents (P<or=0.05) of whey proteins and, particularly, proteose-peptone. The increase of proteose-peptone--per 100 g SNF or 100 g casein--was significantly higher (P<or=0.05) in CF1 than in CF2 and, in particular, than in CF3. A higher increase (P<or=0.05) of resistance to compression was observed in CF1 with respect to CF3. CF2 variation was not different with respect to either CF1 or CF3. Variation of the difference between PS and FC milks (PS-FC) in pH, TBC and fat were clearly lower in CF3 than CF1. This means that the control of milk temperature throughout the whole maturation phase offers a greater control of both microbial development and extent of creaming.
 ...
PMID:Dairy maturation of milk used in the manufacture of Parmigiano-Reggiano cheese: effects on physico-chemical characteristics, rennet-coagulation aptitude and rheological properties. 1847 40

The effect of whey protein concentrate (WPC) and gum tragacanth (GT) as fat replacers on the chemical, physical, and microstructural properties of nonfat yogurt was investigated. The WPC (7.5, 15, and 20 g/L) and GT (0.25, 0.5, 0.75, and 1 g/L) were incorporated into the skim milk slowly at 40 to 45 degrees C with agitation. The yogurt mixes were pasteurized at 90 degrees C for 10 min, inoculated with 0.1% starter culture, and incubated at 42 degrees C to pH 4.6, then refrigerated overnight at 5 degrees C. A control nonfat yogurt and control full fat yogurt were prepared as described, but without addition of WPC and GT. Increasing amount of WPC led to the increase in total solids, total protein, acidity, and ash content, whereas GT did not affect chemical parameters. Increasing WPC caused a more compact structure consisting of robust casein particles and large aggregates. Firmness was increased and susceptibility to syneresis was decreased as WPC increased. No significant difference was observed for firmness and syneresis of yogurt fortified with GT up to 0.5 g/L compared with control nonfat yogurt. Increasing the amount of gum above 0.5 g/L produced softer gels with a greater tendency for syneresis than the ones prepared without it. Addition of GT led to the coarser and more open structure compared with control yogurt.
 ...
PMID:Whey protein concentrate and gum tragacanth as fat replacers in nonfat yogurt: chemical, physical, and microstructural properties. 1856 11

We report physicochemical characteristics of various kinds of liquid milk commercially available in Pakistan in comparison with those of fresh natural milk from animals. Milk samples were collected from local markets at Peshawar, Pakistan, and analyzed for their physical features, including moisture, total solids, specific gravity, conductivity, viscosity and titratable acidity (lactic acid equivalent), and chemical components and macro-minerals, including total protein, casein, lactose, ash and minerals (Na, K and Mg). These items were compared with the physicochemical characteristics of the fresh natural milk samples from buffalo, cow and goat. The results were also compared with reported nutritional quality of milk from various countries and World Health Organization (WHO) standards. We found that all the physical features and chemical components of commercially available milk in Pakistan markets meet WHO's requirements, except for Na, K, Ca and Mg, which are below the standards.
 ...
PMID:Physicochemical characteristics of various milk samples available in Pakistan. 1860 Jul 84

The aim of the study was to estimate the effect of the composite CSN2 and CSN3 genotypes on milk coagulation, quality, and yield traits in Italian Holstein cows. A total of 1,042 multiparous Holstein cows reared on 34 commercial dairy herds were sampled once, concurrently with monthly herd milk recording. The data included the following traits: milk coagulation time; curd firmness; pH and titratable acidity; fat, protein, and casein contents; somatic cell score; and daily milk, fat, and protein yields. A single-trait animal model was assumed with fixed effects of herd, days in milk, parity, composite casein genotype of CSN2 and CSN3 (CSN2-CSN3), and random additive genetic effect of an animal. The composite genotype of CSN2-CSN3 showed a strong effect on both milk coagulation traits and milk and protein yields, but not on fat and protein contents and other milk quality traits. For coagulation time, the best CSN2-CSN3 genotypes were those with at least one B allele in both the CSN2 and CSN3 loci. The CSN3 locus was associated more strongly with milk coagulation traits, whereas the CSN2 locus was associated more with milk and protein yields. However, because of the tight linkage between the 2 loci, the composite genotypes, or haplotypes, are more appropriate than the single-locus genotypes if they were considered for use in selection.
 ...
PMID:Effects of composite beta- and kappa-casein genotypes on milk coagulation, quality, and yield traits in Italian Holstein cows. 1883 28

In Italy, more than 75% of milk is used for cheese making. For this reason, milk composition and coagulation traits and cheese quality represent the most important tools for the economic development of the dairy sector. In particular, cheese quality varies in relation to cheese-making technology and breed of cow. The aim of this study was to investigate the effect of 3 types of milk, originating from Holstein-Friesian (HF), Brown Swiss (BS), and mixed of both breeds, on vat milk characteristics, cheese yield, and quality in 3 different typical Italian cheese-making conditions (Casolet, Vezzena, and Grana Trentino). One hundred forty-four cows (66 HF and 78 BS) were involved, and a total of 24 vats of milk were evaluated. At maturity, 30, 21, and 16 wheels of Casolet, Vezzena, and Grana Trentino cheese were analyzed. Brown Swiss cows yielded 9% less milk per day than HF cows, but milk showed greater contents of protein, casein, titratable acidity, and better rennet coagulation time and curd firmness than HF milk. The chemical composition and cholesterol content of the 3 types of cheese were similar between breeds, whereas the cheese made with BS milk showed greater contents of monounsaturated and polyunsaturated fatty acids. Cheese made with BS milk had greater b* (yellow component) than HF. Cheese yield, recorded at different ripening times, demonstrated that BS milk yielded more cheese than HF. Mixed milk showed values, on average, intermediate to HF and BS milk characteristics, and this trend was confirmed in cheese yield at different ripening times.
 ...
PMID:Effect of Holstein Friesian and Brown Swiss breeds on quality of milk and cheese. 1883 37

Probiotic are microorganisms that, upon ingestion in adequate amounts, exert a beneficial effect on the host. In the present work, the potent probiotic Leuconostoc mesenteroides was used as a starter culture in the preparation of fermented milk beverage. The product was analyzed for protein, titrable acidity, fat, total sugar, fatty acids and minerals. The viability of culture and nutrition in the product was further enhanced with supplementation of adjuvants like tryptone, casein hydrolysate, cysteine hydrochloride and ascorbic acid. After 5 days, maximum viability was observed on supplementation of tryptone (100 mg/l). The protein content was enhanced by 1.1-fold in the presence of tryptone (100 mg/l) as compared with control after 5 days of storage. Fermented milk supplemented with tryptone (100 mg/l) showed maximum bioavailability of the minerals like iron (92.05%), zinc (95.02%) and magnesium (92.04%) as compared with control. The increase in the composition of beneficial fatty acids on supplementation of adjuvants supports the therapeutic value of the product.
 ...
PMID:Supplementation of adjuvants for increasing the nutritive value and cell viability of probiotic fermented milk beverage. 1924 Dec 48

1. A method has been outlined by which the enzymes of hemolytic streptococcus may be extracted with comparative ease. 2. The peptolytic enzyme is active between pH 4.4 and 8.7 with an optimum action at pH 7.2. It is destroyed in neutral phosphate solution at a temperature of 57 degrees C. continued for 10 minutes and at pH 5.0 deteriorates slowly at 37 degrees C. Concentration experiments with solutions of the enzyme have shown that it resembles other enzymes. It is exceedingly susceptible to chloroform and its action is inhibited by dilutions of gentian violet. Casein is attacked but serum albumin is not digested after 3 days at 37 degrees C. 3. The invertase is active between approximately pH 5.0 and 8.0 with an optimum of pH 7.0. It is destroyed by a temperature of 52 degrees C. continued 10 minutes at an acid concentration of pH 7.0, or after 6 hours at 37 degrees C. at pH 5.0. At this acidity it is more susceptible to heat than the peptase. 4. The lipase is active above pH 5.6. The greatest activity was observed at pH 7.9. It is completely destroyed after heating to temperatures over 55 degrees C. for 10 minutes and resembles the invertase in its susceptibility to acid.
 ...
PMID:THE PEPTASE, LIPASE, AND INVERTASE OF HEMOLYTIC STREPTOCOCCUS. 1986 48

In this study, 2 different starter culture combinations were prepared for cheesemaking. Starter culture combinations were formed from 8 strains of lactic acid bacteria. They were identified as Lactococcus lactis ssp. lactis (2 strains), Lactobacillus plantarum (5 strains), and Lactobacillus paraplantarum (1 strain) by amplified fragment length polymorphism analysis. The effects of these combinations on the physicochemical and microbiological properties of Beyaz cheeses were investigated. These cheeses were compared with Beyaz cheeses that were produced with a commercial starter culture containing Lc. lactis ssp. lactis and Lc. lactis ssp. cremoris as control. All cheeses were ripened in brine at 4 degrees C for 90 d. Dry matter, fat in dry matter, titratable acidity, pH, salt in dry matter, total N, water-soluble N, and ripening index were determined. Sodium dodecyl sulfate-PAGE patterns of cheeses showed that alpha(S)-casein and beta-casein degraded slightly during the ripening period. Lactic acid bacteria, total mesophilic aerobic bacteria, yeast, molds, and coliforms were also counted. All analyses were repeated twice during d 7, 30, 60, and 90. The starter culture combinations were found to be significantly different from the control group in pH, salt content, and lactobacilli, lactococci, and total mesophilic aerobic bacteria counts, whereas the cheeses were similar in fat, dry matter content, and coliform, yeast, and mold counts. The sensory analysis of cheeses indicated that textural properties of control cheeses presented somewhat lower scores than those of the test groups. The panelists preferred the tastes of treatment cheeses, whereas cheeses with starter culture combinations and control cheeses had similar scores for appearance and flavor. These results indicated that both starter culture combinations are suitable for Beyaz cheese production.
 ...
PMID:Genotypic identification of some lactic acid bacteria by amplified fragment length polymorphism analysis and investigation of their potential usage as starter culture combinations in Beyaz cheese manufacture. 2005 97

The effects of storage temperature (+4 degrees C and -18 degrees C) and packaging method (nonvacuum and vacuum) on biogenic amines in Motal cheese during storage periods were investigated. In addition, dry matter, titratable acidity, total nitrogen, water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, free amino group (proteolysis), electrophoretic patterns of casein, and amounts of lactic acid bacteria and coliforms were determined. Storage period had a significant effect on all of the biogenic amines. When compared with vacuum packaging, normal packaging had higher amounts of putrescine, cadaverine, histamine, and tyramine. Coliforms were not found at detectable levels (<100cfu/g) in all cheese samples. Results of urea-PAGE analysis of cheese samples were in good agreement with biogenic amine results and other proteolysis parameters.
 ...
PMID:The effect of storage temperatures and packaging methods on properties of Motal cheese. 2017 4

The increasing demand for animals from organic breeding systems has increased interest in certain natural substances, called nutraceuticals, to stimulate the organic defenses of the animals. The aim of this trial was to study the effects of dietary rosemary extract in 36 ewes, from 57 to 154 days of lactation, divided into three groups: CTR (basal diet), ROXLD (600 mg extract/head/day) and ROXHD (1,200 mg extract/head/day). A significantly higher quantity of milk and quantitative daily production of protein, casein, fat, and lactose were observed in the milk of animals in the ROXHD group compared with milk from animals in the CTR and ROXLD groups. No significant differences were observed for somatic cell counts, considering that treated groups showed lower values compared with controls. A significant decrease in clotting time (r) and increase in curd firmness (a ( 30 )) were observed in milk of both treated groups (ROXLD and ROXHD) compared with the CTR group. These results could be related to the significantly higher acidity values, pH and SH degrees , observed in the milk of animals from the treated groups. Dietary rosemary extract in dairy sheep enhanced milk yield, quality, and renneting properties due to its "natural, functional ingredients."
 ...
PMID:Organic management of dietary rosemary extract in dairy sheep: effects on milk quality and clotting properties. 2043 65


<< Previous 1 2 3 4 5 6 7 8 Next >>