• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.449-453
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• 1990

This study was attempted to obtain the efficient milk-clotting enzyme from microorganisms as a rennet subtitute. Fungi which showed the formation ability of the milk-clotting enzyme were selected out from samples of soil hay and wastes etc. Among these isolated fungi, strain no. C-7 which had presented higher value in the ratio of milk-clotting activity to proteolytic activity was selected. The hyphae of this strain was white to gray and no septa. A single sporangiophore which stand erectly above growing hyphae was monomucor type without branching. A globose sporangium was developed at the tip of each sporangiophore. The suitable temperature and pH for the growth of no. C-7 was 20-$30^{\circ}C$ and pH 3.0-8.0 respectively. These morphological and physiological characteristics implied that strain no. C-7 was Mueor mucedo.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.738-742
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• 2003

The monitoring was carried out for one year on 20 farms of Mediterranean buffalo situated in central Italy. The milk yield, the somatic cell count, the coagulating properties and some components were determined. The average value of somatic cells was $21.28n{\times}10^3/ml$. Milk production decreased when somatic cell numbers increased. The rennet clotting time increased significantly when somatic cells were higher than $300.00n{\times}10^3/ml$, the curd firming time was significantly higher when somatic cells were more than $1,000.00n{\times}10^3/ml$ and the curd firmness increased up to $200.00n{\times}10^3$/ml, then gradually decreased. Protein and casein decreased when somatic cells increased and the same trend was shown by casein/protein ratio. Both for these components and the coagulating properties the threshold limit of somatic cells to obtain better results was $200.00n{\times}10^3/ml$. The somatic cell number did not show a trend which was strictly influenced by the lactation stage, contrary to what happened in the other species.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.551-559
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• 2010

Among the food constituents, proteins differ in coagulation properties as compared to other constituents in food system. Especially milk protein coagulate through different pathways thus this coagulability can be used for manufacture of various dairy products or as a determinant of dairy product analysis. These milk coagulation methods include organic solvent, isoelectric point, trichloroacetic acid, Ca-sensitive casein, heavy metal ion and rennet coagulation. The coagulation experiment was performed using above parameters at $0^{\circ}C$ and $25^{\circ}C$ to find the dehydration conditions before coagulating for precheese powder making. After different chemical treatments, there was no coagulation at $0^{\circ}C$ rather at $25^{\circ}C$ whatever the mode of coagulation methods was. The appearance of precipitate with coagulation methods was quite different from above mentioned methods of coagulation illustrated by scanning electron microscope. These powders were used for fabrication of camembert cheese by renneting coagulation at $0^{\circ}C$, showing the possibility of cheese materials and of food additives for fabrication of products.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1227-1232
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• 2011

The objective of this study was to examine the effects of concentrates containing different levels of a vitamin-trace elements premix on milk yield and composition of dairy cows. The trial, which lasted 14 weeks, was conducted from January to March and used 45 multiparous Brown cows in the early phase of lactation. Cows (n = 15 per treatment) were randomly allocated to three dietary treatments: the first group (control, C-0) was fed pelleted concentrate containing background vitamins and trace elements that supplied 1.0 times cows' daily requirements; the second group were fed the same concentrate, but containing 2.5 g/kg of vitamin and trace mineral premix per kg of concentrate (C-2.5); the third group were fed the same concentrate, but containing 5 g/kg of vitamin and trace mineral premix per kg of concentrate (C-5). The daily ration included ad libitum chopped oat hay, and the cows also had 8 h/d grazing on a ryegrass (Lolium multiflorum) pasture. During the performance trial, cow milk yield was daily recorded and individual milk samples were analysed for milk composition and to determine milk renneting properties. Cows fed the intermediate premix level (C-2.5) in diet showed the highest fat-corrected milk production (p<0.05) compared to other groups. None of the milk quality parameters studied were influenced by dietary treatment, except for milk rheological parameters (rennet clotting time and curd firmness) that were positively improved in cows fed the C-2.5 diet (p<0.05). The findings from this study show that intermediate level of vitamin-trace elements premix in concentrate can be advantageously used in grazing dairy cows without negative effects on yield and quality of milk produced.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1084-1091
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• 2013

In this paper, two statistical methods were applied to optimize medium components to improve the production of the milk-clotting enzyme by Bacillus amyloliquefaciens D4. First, wheat bran juice, skim milk powder, and $Na_2HPO_4$ were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, an optimal medium was obtained using the Box-Behnken method, which consisted of 3.31 g/l of skim milk powder, 5.0 g/l of sucrose, 0.1 g/l of $FeSO_4{\cdot}7H_2O$, 0.1 g/l of $MgSO_4{\cdot}7H_2O$, 0.1 g/l of $MnSO_4{\cdot}2H_2O$, 0.1 g/l of $ZnSO_4{\cdot}7H_2O$, 1.52 g/l of $Na_2HPO_4$, and 172.45 g/l of wheat bran juice. With this optimal medium, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 3,326.7 SU/ml after incubation of 48 h, which was 1.76-fold higher than that of the basic medium, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize medium components, and B. amyloliquefaciens D4 possessed a high rennet-producing capacity in the optimal medium.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.245-251
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• 1988

Thermolysin was immobilized on Dowex MWA-1 with 10% glutaraldehyde and incorpo rated into a fluidized-bed continuous coagulation scheme to make Cheddar type cheese. The activity yield of thermolysin was 25%. The immobillized thermolysin was stable at $60^{\circ}C$ in the presence of 1/200M calcium ions and the half-life value is 16 days at the temperature. Raw milk alkalified to pH 7.0 was passed through a column of thermolysin beads at $55^{\circ}C$, cultivated with Streptococcus cremoris and allowed to coagulate. A typical milk curd was formed to make Cheddar type cheese, avoiding troublesome microbial contamination successfully during continuous hydrolysis process. During ripening of this cheese for 6 months at $10^{\circ}C$, its ripening ratio and taste were similar to those of cheese prepared by the traditional method.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1404-1411
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• 2020

Lactic acid bacteria (LAB) play an important role in dairy fermentations, notably as cheese starter cultures. During the cheese production and ripening period, various enzymes from milk, rennet, starter cultures, and non-starter LABs are involved in flavor formation pathways, including glycolysis, proteolysis, and lipolysis. Among these three pathways, starter LABs are particularly related to amino acid degradation, presumably as the origins of major flavor compounds. Therefore, we used several enzymes as major criteria for the selection of starter bacteria with flavor-forming ability. Lactococcus lactis subsp. lactis LDTM6802 and Lactococcus lactis subsp. cremoris LDTM6803, isolated from Korean raw milk and cucumber kimchi, were confirmed by using multiplex PCR and characterized as starter bacteria. The combinations of starter bacteria were validated in a miniature Gouda-type cheese model. The flavor compounds of the tested miniature cheeses were analyzed and profiled by using an electronic nose. Compared to commercial industrial cheese starters, selected starter bacteria showed lower pH, and more variety in their flavor profile. These results demonstrated that LDTM6802 and LDTM6803 as starter bacteria have potent starter properties with a characteristic flavor-forming ability in cheese.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.202-207
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• 1993

Ginseng-whey beverages were prepared with rennet whey, ginseng extract, sweetener, honey and Japanese apricot, inoculated with different strains of lactic acid bacteria and unfermented partly. The samples were stored at 4$^{\circ}C$ or 30$\pm$1$^{\circ}C$ and the sensory evaluations were carried out at 1st, 3rd and 5th week. As a result of sensory test, unfermented ginseng-whey beverage (A) with sweetener and honey (storage at cold temp.) in overall eating quality obtained the best score (8.64~8.86) due to stronger sweetness and weaker sourness, bitterness, astringent taste and aftertaste. The fermented ginseng-whey beverage (C) which was stored at 4$^{\circ}C$ with inoculation of Lac. acidophilus and Lac. delbrueckii sub-sp. bulgaricus and the unfermented samples stored at room temperature with sweetener, honey and Japanese apricot received a good evaluation. But, the fermented beverages (E, F) stored at room temperature obtained the lowest score (2.92~3.58).

• Food Science of Animal Resources
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• v.39 no.4
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• pp.541-554
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• 2019

Processed cheeses (PCs) were made under varying cooking pH values (5.3, 5.4, 5.5, and 5.6) using a processed cheese cooker. Along with emulsifying salts (2.5%), distilled water, NaCl (2%) and a colouring agent under these cooking pH values, the PC samples made with either 100% fresh curd and rennet casein coded processed cheese control ($PC_C$) as control or ~70% fresh curd-~30% traditional village cheese coded processed cheese with village cheese ($PC_V$). The main aim of this study was to determine the effect of the varying cooking pH values on the textural properties for the PCv samples compared with the control sample during 90 days of storage. Chemical and textural properties of all PC samples were investigated over time. The chemical compositions of the PC samples (dry matter and ash) increased at d 90 of storage significantly, due to 1-d ripening of all PC samples at ambient temperature in terms of the manufacturing protocol of the cheese. The textural properties of the PC samples were altered by the varying cooking pH values. It may propose that the interactions of the proteins at the cooking pH values during processing and biochemical mechanisms in the cheese systems could likely affect the texture of the PC samples over time. Hardness, gumminess and chewiness values of all PC samples also increased over time (p<0.05). This study is also to give some knowledge on the design of PC manufacture to cheese makers, and a marketing opportunity to local cheese makers who individually make a traditional village cheese in Turkey.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.215-221
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• 2015

This study aimed to establish the optimum culture conditions for Mozzarella cheese by using Streptococcus macedonicus LC743, a strain selected for its immunomodulatory activity. For process optimization, 1.0% and 2.0% strain was inoculated and incubated at $32^{\circ}C$ and $35^{\circ}C$, respectively. The general components, bacterial count, total solids, yields, and immunomodulatory activity of the Mozzarella cheese were investigated. When the strain was inoculated at 2.0% and incubated at $32^{\circ}C$, the product quality and immunomodulatory activity was optimal and required minimal processing time. Therefore, 2.0% of S. macedonicus LC743 starter culture was added to milk at $32^{\circ}C$, after pasteurization at $63^{\circ}C$ for 30 min, and agitated for 4~5 min after addition of $230{\mu}L/kg$ of rennet. Curd was made by setting the milk 25~35 min after addition of 0.01~0.02% calcium chloride. The curd was cut at 0.1~0.12% acidity (81 min later) and after heating the cheese to up to $43^{\circ}C$. Whey was removed at an acidity of 0.17~0.18% by agitation for 53 min. Next, cheddaring for 210 min up to an acidity of 0.6~0.65%, stretching at $72{\sim}75^{\circ}C$, and molding at $65{\sim}70^{\circ}C$ were performed, and the product was allowed to cool down to $5^{\circ}C$. Salting was done with a solution of $18{\sim}20^{\circ}B{\acute{e}}$ at $12^{\circ}C$ for 20 min and drying occurred at 80~90% relative humidity at $10^{\circ}C$ for 2~3 days.