• Korean Journal of Food Science and Technology
• /
• v.23 no.4
• /
• pp.471-477
• /
• 1991

The optimum conditions for the development of a lactic acid beverage from the concentrated whey were studied using reverse osmosis system. For lactose hydrolysis rate and acid productivity, the strain mixture of Streptococcus thermophilus and Lactobacillus bulgaricus was more efficient than that of Streptococcus cremoris and Streptococcus lactis. The titratable acidity was increased at higher LCR (lactose concentration ratio) of whey. However, the higher LCR of whey was, the slower the pH decreasing rate was. The amount of sediment was maximum at LCR of 1.0 : 1 whey, hit there was no sediment at LCR 3.0 : 1 whey after 12 hours. Propylene glycol alginate was the best stabilizer and prevented from sedimentation at the concentation of less than 0.1%. Aspartame as a sweetener of yoghurt flavor had the best palatability.

• KSBB Journal
• /
• v.26 no.6
• /
• pp.529-532
• /
• 2011

Whey based medium was optimized for the production of viable Lactobacillus crispatus KLB 46 isolated from the vagina of Korean women. Among the various nitrogen sources such as yeast extract, beef extract, and proteose peptone no. 3 supplemented to whey, beef extract showed the highest viable cell production. The addition of Tween 80 to the whey based medium increased viable cell concentration. As beef extract supplementation is not economically attractive, corn steep liquor was added as a supplementary nitrogen sources. When corn steep liquor was supplied with beef extract with the ratio 5 : 1, the viable cell count was $3.11{\times}10^9$ CFU/mL. Also, the addition of mineral salts containing sodium acetate (5 g/L), potassium phosphate dibasic (2 g/L), magnesium sulfate (0.1 g/L) and manganese sulfate (0.05 g/L) to the whey medium increased viable cell count further ($5.00{\times}10^9$ CFU/mL).

• Food Science of Animal Resources
• /
• v.35 no.3
• /
• pp.350-359
• /
• 2015

This review focuses on the enhanced functional characteristics of enzymatic hydrolysates of whey proteins (WPHs) in food applications compared to intact whey proteins (WPs). WPs are applied in foods as whey protein concentrates (WPCs), whey protein isolates (WPIs), and WPHs. WPs are byproducts of cheese production, used in a wide range of food applications due to their nutritional validity, functional activities, and cost effectiveness. Enzymatic hydrolysis yields improved functional and nutritional benefits in contrast to heat denaturation or native applications. WPHs improve solubility over a wide range of pH, create viscosity through water binding, and promote cohesion, adhesion, and elasticity. WPHs form stronger but more flexible edible films than WPC or WPI. WPHs enhance emulsification, bind fat, and facilitate whipping, compared to intact WPs. Extensive hydrolyzed WPHs with proper heat applications are the best emulsifiers and addition of polysaccharides improves the emulsification ability of WPHs. Also, WPHs improve the sensorial properties like color, flavor, and texture but impart a bitter taste in case where extensive hydrolysis (degree of hydrolysis greater than 8%). It is important to consider the type of enzyme, hydrolysis conditions, and WPHs production method based on the nature of food application.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.3
• /
• pp.436-445
• /
• 2015

The effects of substituting whey protein concentrate (WPC) powder for rice flour in the preparation of seolgiddeok were determined by objective and subjective tests. Milk whey is drained from milk curd as a by-product of the cheese manufactureing process. Whey protein is known as a good nutritional source and is a functional material for many processed foods. WPC contains more than 80% whey protein. The moisture content decreased gradually during storage and the decrease in moisture was less in the control than in the WPC powder substituted groups. The color lightness (L) decreased significantly as the amount of WPC powder increased, wherease redness (a) and yellowness (b) both increased. Texture analyses revealed that the hardness, chewiness, gumminess and adhesiveness of seolgiddeok tended to increase in proportion to the amount of WPC powder in the formula. Seolgiddeok gelatinization was investigated by amylographing. Initial pasting temperature, peak viscosity, hot pasting viscosity and breakdown were low in seolgiddeok prepared with WPC powder substituted for rice flour. Setback had the lowest value in the control. Sensory evaluations revealed that, seolgiddeok prepared with 3% WPC powder had the highest overall acceptability score. These results indicated that WPC seolgiddeok with 3% WPC powder has the best quality.

• Journal of the Korean Society of Food Culture
• /
• v.24 no.5
• /
• pp.561-569
• /
• 2009

The effects of substituting whey protein isolate (WPI) powder for rice flour during the preparation of paeksulgi (Korean rice cake) were evaluated by objective and subjective tests. Milk whey is drained from milk curd as a by-product of the cheese manufacturing process. Whey protein is known as a good nutritional source and a functional material for many processed foods. WPI contains more than 90% whey protein. The moisture content decreased gradually during storage and the decrease was less in control than WPI powder-substituted groups. The color lightness (L) decreased significantly with increasing WPI powder, wherease the redness (a) and yellowness (b) both increased. Texture analyses revealed that the hardness, chewiness, gumminess, adhesiveness and fracturability of paeksulgitended to increase in proportion to the amount of WPI powder added. Evaluation of the gelatinization of paeksulgi by amylographing revealed that the initial pasting temperature, peak viscosity, hot pasting viscosity and breakdown was lower in samples that contained WPI powder. However, the lowest setback value was observed in the control. The results of the sensory evaluation indicated that paeksulgi prepared with 2% WPI powder had the highest overall acceptability. Taken together, these results suggest that WPI paeksulgi containing 2% WPI powder has the best quality.

• Korean Journal of Food Science and Technology
• /
• v.25 no.5
• /
• pp.510-516
• /
• 1993

This study was conducted to investigate biochemical characteristics of enzyme-added cheese base slurries during accelerated ripening. Trichloroacetic acid (TCA) soluble nitrogen of cheese base slurries increased rapidly during the first day of ripening and the rate of increase slowed down thereafter. Cheese base slurries showed lower level in the production of the nitrogen than Cheddar cheese slurries. Producctions of phosphotungstic (PTA) soluble amino nitrogen also showed similar trends as TCA soluble nitrogen. Electrophoresis revealed that all caseins in both cheese base slurries and Cheddar cheese slurries were hydrolyzed, but whey proteins in cheese base slurries were little hydrolyzed. Cheese base slurries produced free amino acids little more than half of Cheddar cheese slurries. Both slurries showed similar increasing trend in production of short-chain free fatty acids. The specificity of the fatty acids in the slurries was similar to that of natural ripened cheese. The results of this study showed that addition of enzyme was effective to accelerate cheese base ripening.

• Food Science of Animal Resources
• /
• v.33 no.5
• /
• pp.565-571
• /
• 2013

An enzyme ${\beta}$-galactosidase or ${\beta}$-galactohydrolase [EC3.2.1.23], commonly called lactase, mediates galacto-oligosaccharide (GOS) synthesis under conditions of high substrate concentrations. Also, lactase hydrolyzes ${\beta}$($1{\rightarrow}4$) lactose into glucose and galactose, the latter is successively transferred to free lactose to make various oligosaccharides via transgalactosylation. GOS is non-digestible to human digestive enzymes and has been used as a functional prebiotics. Among the 24 lactic acid bacteria (LAB) strains used, Lactobacillus paracasei YSM0308 was selected based on its exhibition of the highest ${\beta}$-galactoside hydrolysis activity, and the crude lactase was prepared for examination of reaction conditions to affect the GOS synthesis. Lactase activity was measured with a spectrophotometer using ONPG (o-nitropheyl ${\beta}$-D-galactopyranoside) method. Lactase activity was not detected in the culture supernatant and was mostly present in the cell pellet after centrifugation. Activity of the crude lactase preparation ranges from102 to 1,053 units/mL, with the highest activity determined for L. paracasei YSM0308. Optimal conditions for GOS synthesis are as follows: concentration of whey powder, pH, temperature, and time were 30%, pH 6.5-7.0, $30^{\circ}C$, and 4 h, respectively. The final GOS concentration was 19.41% (w/v) by the crude YSM0308 lactase, which was obtained from strain YSM0308 grown in the 10% (w/v) reconstituted whey-based medium.

• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.878-884
• /
• 1995

In order to use whey lactose in alcohol fermentation, we investigated fermentation conditions of Saccharomyces cerevisiae and Kluyveromyces fragilis in lactose-hydrolyzed whey with ${\beta}-D-galactosidase$. and optimum conditions of the above two yeasts through oxygen regulation by Pasteur effect which is the characteristic of the yeasts were determined. In addition, optimum condition for application of fermented whey in Tak-ju process was also examined. With 0.7% ${\beta}-D-galactosidase$, 93% lactose was hydrolyzed at pH 6.5 in 30 minutes. Because S. cerevisiae is unable to ferment galactose, the production of ethanol by S. cerevisiae was lower than that of K. fragilis in lactose-hydrolyzed whey. But ethanol productivity by S. cerevisiae was higher than that by K. fragilis in glucose added whey. In fermentation with oxygen regulation and addition of 60 g/l glucose, the ethanol productivity of K. fragilis and S. cerevisiae were 18.9 g/l (11.8% increase) and 43.5 g/l (22.1% increase), respectively. It appeared that the ethanol productivity of S. cerevisiae was higher than thst of K. fragilis under the above conditions. In ethanol fermentation added rice starch, Aspegillus oryzae hydrolyzed 80% of starch in 60 hours, and the production of ethanol was 80.2 g/l

• Korean Journal of Agricultural Science
• /
• v.50 no.2
• /
• pp.281-294
• /
• 2023

As a byproduct obtained from cheese manufacture, whey protein was developed as a functional food that contains multi-functional proteins. In this study, the biochemical activity of fermented milk prepared by fortifying whey protein with excellent physiological activity was investigated. Immunoglobulin (IgG) content was higher in 10% fortified whey protein fermented milk than in the control. The viable cell counts were 20% higher in the fermented milk with 10% fortified whey protein than in the control group. The antibacterial effect of 10% fortified whey protein fermented milk compared to the control group was shown to be effective against four pathogenic microorganisms, Escherichia coli (KCTC1039), Pseudomonas aeruginosa 530, Salmonela Typhimurium (KCTC3216), and Staphylococcus aureus (KCTC1621). The antioxidant effect by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities wasincreased two-fold in 10% fortified whey protein fermented milk compared to the control. The 10% fortified whey protein fermented milk inhibited the expression of the inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and induced nitric oxide synthase [iNOS]) in a concentration-dependent manner. In a piglets feeding test, the weight gain with 10% fortified whey protein fermented milk was increased by 18% compared to the control group, and no diarrhea symptoms appeared. Our results clearly demonstrated that 10% fortified whey protein fermented milk could be a useful functional ingredient for improving health.

• Journal of Dairy Science and Biotechnology
• /
• v.16 no.2
• /
• pp.106-118
• /
• 1998

Whey is a natural product obtained during cheese production. With the advent of new technology, whey protein concentrates and whey fractions have become readily available and versatile food ingredients. Whey protein concentrates are highly functional ingredients that have gelling, emulsifying, whipping, water-binding and fat-replacement properties. New fractions derived from whey (such as alpha-lactalbumin, lactoferrin, lactoperoxidase and peptides) attract considerable interest worldwide because of their bioactive or health-enhancing properties. Some of these fractions also find new uses as natural antibiotic, natural preservative and immunity-enhancing agents. With the growth of the functional foods industry sector, an increasing number of manufacturers take advantage of whey's nutritional and functional benefits to develop successful new products. The United States is the world's largest single producer and exporter of whey products. In 1997, more than 1 million metric tons of whey products were manufacturers in the U.S.