• 한국식품영양학회지
• /
• 제20권4호
• /
• pp.349-355
• /
• 2007

Periodate-oxidized soluble starch was reacted with papain at pH 4.0, pH 7.0, and pH 9.7, and an oxidized soluble starch-papain conjugate was produced. When compared with native papain, the specific activity decreased to 60%, in both the modified papain reacted with 0.4% $NaBH_4$ and in the modified papain not reacted with $NaBH_4$. The specific activity decreased to 70% in the modified papains reacted with 1.5% $NaBH_4$ and 4.0% $NaBH_4$, respectively. The reduction by $NaBH_4$ did not have an effect in the thermal stability of either the modified or nonmodified papain. An activity of 54.7% remained in the papain modified at pH 4.0, which was incubated at $80^{\circ}C$ for 40 min. The papains modified at pH 7.0 and pH 9.7 and incubated for 40 min at two different temperatures, respectively, were stable to $60^{\circ}C$, and at $80^{\circ}C$ their activities at 56.3% and 44.1 %, respectively. The modified papain's thermal stability pattern was similar to that of native papain, with no increase in its statbility. In the range of pH $2.0{\sim}13.0$, the stability of the papain modified at pH 4.0 decreased greatly between pH $3.0{\sim}5.0$, but it was similar to the native papain at other pH values. The stability of the papain modified at pH 7.0 showed a similar pattern to the native papain at pH $2.0{\sim}6.0$, while its stability increased when moving into the alkali pH range. The papain modified at pH 9.7 also had increased stability, when moving into the alkali range. The results of Hammerstein milk casein, which was reacted with the papains modified at pH 4.0, pH 7.0, and pH 9.7, respectively, and analyzed by FPLC, showed different peaks according to the different modification pHs, and the greatest peak differences were observed with the modification at pH 9.7.

• Journal of Dairy Science and Biotechnology
• /
• 제24권2호
• /
• pp.39-45
• /
• 2006

산양유제품은 산양의 산간 방목지에서 천연의 산야초를 먹는 먹이습성으로 인하여 웰빙식품의 개념으로 뿐만 아니라 산양유 조제식의 형태로 다시 소비되기 시작하고 있다. 우유와 산양유의 조성에는 주요 영양성분의 경우 특별한 차이를 보이지 않는다. 그러나 젖소와 산양의 젖은 케이신 마이셀의 공간구조, 케이신 단백질의 아미노산 조성, 마이셀의 크기, 마이셀의 미네랄 함량 등에 있어서 명백한 차이를 보인다. 산양유제품의 국내생산은 연중 착유가 어려워 소비자에게 연중 공급이 불가능한 문제가 중요한 점으로 대두되고 있다. 그 어려움 속에서 산양유 시장의 확대를 추구하기 위해서는 산양유 제조사들의 집중적인 홍보가 필요하다. 국내 소비시장의 특징은 산양유 소비형태가 주로 신선유로서 소비되며, 발효유로서는 일부만 소비된다는 점이다. 이러한 제품들은 주로 소규모 산양유가공회사에서 생산되며, 대규모 유가공회사에서는 소요량이 많은 산양조제분유 생산에 치중하고 있는 점 또한 특징이라고 할 수 있다. 앞으로 산양유제품의 확대를 위해서는 유가공기술분야의 전문인들에 의해서 한국소비자들에게 적합하지 않은 산양 특유의 불쾌한 냄새와 맛을 제거하는 연구와 기술이 개발되어야 할 것으로 판단된다.

• Journal of Dairy Science and Biotechnology
• /
• 제31권1호
• /
• pp.21-33
• /
• 2013

The purpose of this study was to improve the production of Mozzarella cheese analogues manufactured using mixtures of soy milk and concentrated raw milk by performing ultrafiltration (UF) and to assess the quality of these cheeses during a 30-day storage period at $4^{\circ}C$, relative to that of Mozzarella cheese manufactured with the traditional method. The solid consistency of Mozzarella cheese analogue prepared from milk mixtures was lower than that of cheese manufactured from raw milk or soy milk and increased during storage, which is considered to be the result of decreasing water levels, as well as with increasing soy milk concentrations. In the Mozzarella cheese analogue generated using the milk mixtures, the fat content decreased with increase in the soy milk concentration, while it decreased during the storage period. Lactose levels were lowest in cheese composed of soy milk or raw milk and processed by UF, and decreased during storage in cheese produced using milk mixtures. In milk mixtures containing soy milk, the protein concentration increased with increasing amounts of raw milk and did not change during the storage period. The water-soluble nitrogen compound level was similar between cheeses and increased only slightly during storage. The amount of non-protein nitrogen compounds was higher in the cheese analogue than in the control cheese and tended to increase during storage. Analysis of the physicochemical traits of the Mozzarella cheese analogue yielded the following results: During storage, titratable acidity levels increased while pH tended to decrease. After analysis using electropherograms, it was classified as ${\alpha}$-, ${\beta}$-, or ${\kappa}$-casein. The results of rheometry tests showed that in the Mozzarella cheese analogue prepared from milk mixtures, with raw milk concentrated by UF, increases in concentration rate lead to lowered hardness, elasticity, cohesiveness, and brittleness. When cheese was produced from milk mixtures and concentrated by UF, meltability increased as the concentration rate increased, although to an extent that was less than that observed for the control cheese, and tended to increase during storage. Sensory evaluation showed that the analogue cheese was much better than the control cheese in terms of formation, appearance, and flavor.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권12호
• /
• pp.1798-1807
• /
• 2002

This study was conducted to investigate lactobacillus salivarius subsp. salivarius having probiotic properties to be used as the health adjuncts with fermented milk products. Acid- and bile-tolerant lactobacillus salivarius subsp. salivarius was isolated with lactobacilli MRS broth from faeces of 80 healthy persons (infants, children and adults). It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at 37$^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by 0.9-1.0% at 37$^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced 23-38% of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 h at 37$^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with 15-25 mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권8호
• /
• pp.1138-1143
• /
• 2001

A total of 96 piglets were weaned at 19 and 13 days in Exp. 1 and 2, respectively, and allotted to one of four diets: three with different spray dried plasmas (SPs) and one with hydrolysed casein (HC). SPs were from pigs (SPP), mixed origin (SMP), and mixed origin with standardized level of immunoglobulins (SMPIG). All the diets contained 1.7% total lysine, 25% of the test protein source, 45% corn starch, 15% lactose, 2% sucrose, 7% soybean oil. At d 4 and d 2 in Exp. 1 and 2, respectively, piglets were perorally challenged with $10^{10}$ CFU E. coli K88. Growth performance, immunity, and health condition were measured for 15 days and 14 days in Exp. 1 and 2, respectively. To investigate apparent ileal digestibility and nutrient deposition, all piglets were sacrificed at d 14 in Exp. 2. In 1. 3 piglets died in HC diet and 1 in SPP diet. HC diet showed higher mortality (p<0.01) than other diets. In Exp. 2, no clinical sign of infection was detected, no difference for the content of E. coli K88 was found in feces at 4 and 6 days after the infection, and no E. coli K88 was found in the jejunum at the end of experiment. In both experiments, feed intake was lower for HC diet and ADG was 96, 106, 122 and 155 for HC, SPP, SMP and SMPIG diet, respectively (HC vs others, p<0.05; SMPIG vs other SP, p<0.01). Heal apparent digestibility of nitrogen in sacrificed piglets was higher for HC diet (p<0.05). After the challenge, K88-specific titers in saliva (Exp. 1) and in plasma (Exp. 2) were reduced in SMP and SMPIG. The piglets positive to the adhesion of the used E. coli strain to the intestinal brush borders had a significantly reduced growth (p<0.01) and a higher K88-specific IgA titer in plasma, in comparison with negative ones. This effect was independent of the diet. The data show the relevance of spray dried plasma sources and particularly of SP with standardized level of immunoglobulins for the feeding of early-weaned at the risk of infection by enterotoxigenic bacteria.

• 한국수산과학회지
• /
• 제44권1호
• /
• pp.18-24
• /
• 2011

This study investigated the physicochemical and enzymatic properties of unmarketable cultured bastard halibut (Paralichthys olivaceus) of different weights as a potential source of surimi and surimi gel. The proximate composition of cultured bastard halibut of different weights did not differ significantly at P<0.05 (light weight (LBH) 400~500 g, medium weight (MBH) 600~800 g, and heavy weight (HBH) > 1,000 g). Compared to Alaska pollock muscle, the bastard halibut muscle had a 4% higher crude protein content and 6% lower moisture content. The collagen content of LBH bastard halibut muscle was 1.58 g/100 g, which was lower than or no different from bastard halibut weighing different amounts. Regardless of fish weight or pH, the enzymatic activities of crude fish extracts ranged from 0.34~0.48 U/mg for casein and hemoglobin, 11.0~12.7 U/mg for LeuPNA, 5.4~6.1 U/mg for ArgPNA, 2.3~2.9 U/mg for SAAPFNA, and 0.1~0.2 U/mg for BAPNA. The yield of surimi gel from LBH was 24.4%, which was similar to that from MBH and lower than that from HBH. The surimi gel from LBH was similar to that from HBH, while weaker than that from MBH. The surimi gel from LBH gel was stronger than grade SA gel from commercial Alaska pollock.

• 한국수산과학회지
• /
• 제44권3호
• /
• pp.191-196
• /
• 2011

In this study, we investigated the chemical and enzymatic properties of unmarketable cultured bastard halibut (UCBH) Paralichthys olivaceus harvested at different times (March, May, July, September, November, and January), and we examined the physical properties of surimi gel from UCBH as a potential source of surimi and surimi gel. The moisture and crude protein contents of UCBH harvested in July and January were >78% and <19%, respectively, which is greater than the moisture content in UCBH harvested in May, March, and September, but lower than the crude protein content. Regardless of the month of harvest, the UCBH had a higher crude protein content than Alaska pollock, which is the largest fishery biomass used for surimi and surimi gel, but a lower moisture content. Regardless of the month of harvest, the enzymatic activity in crude extracts of UCBH muscle ranged from 0.31-0.59 U/mg for casein (pH 6.0 and 9.0) and 11.7-12.7 U/mg for LeuPNA. These findings suggest that autolytic enzymes were unaffected by gel formation. Gel strength was highest in the surimi gel prepared from UCBH harvested in September, November, and January; second highest in that prepared from UCBH harvested in March and May; and lowest in that prepared from UCBH harvested in July. Compared to the gel strength of surimi gel from grade SA commercial Alaska pollock surimi, the strength of the surimi gels prepared from UCBH harvested in March, May, September, November, and January were superior, whereas that of the surimi gel prepared from UCBH harvested in July was similar.

• 한국수산과학회지
• /
• 제50권6호
• /
• pp.812-817
• /
• 2017

This study evaluated the effects of dietary inclusion of soybean (SM) and fermented soybean meal (FSM) on growth promotion in juvenile abalone Haliotis discus. Six hundred and thirty juvenile abalone were distributed into nine plastic containers. Three diets were prepared with 22% fish meal, 2% casein, and either 25% SM or FSM used as the protein sources in the experimental diets, and Undaria was used as a control diet to compare the effects of the experimental diets on the growth performance of abalone. The diets were assigned to three containers each and fed to the abalone once daily to satiation for 16 weeks. Weight gain and specific growth rate (SGR) were higher in abalone fed the SM diet than in those fed the FSM diet. Weight gain and SGR of abalone fed the SM and FSM diets were higher than those of abalone fed Undaria. The crude protein and lipid contents of the edible portions of abalone fed the SM and FSM diets were higher than those of abalone fed Undaria. SM was superior to FSM as a protein source in abalone feed. The SM and FSM diets facilitated greater growth than Undaria.

• 한국식품영양과학회지
• /
• 제35권4호
• /
• pp.410-415
• /
• 2006

청국장 분말이 고지방식이를 섭취한 흰쥐의 지질대사에 미치는 영향을 조사하고자, 성숙한(생후 20주령) 숫쥐를 4주간 고지방식이(0.5% 콜레스테롤, 10% 지방)로 고지혈증을 유도한 후 대조군(고지방식이), 청국장군(고지방식이에 단백질원으로 청국장 분말을 첨가한 식이) 및 상황버섯 청국장군(고지방식이에 단백질원으로 상황버섯 청국장 분말을 첨가한 식이 ) 등 3군으로 나누어 5주간 사육한 결과는 다음과 같다. 실험동물의 체중은 대조군이 41.8 g증가함에 비하여 청국장군 및 상황버섯 청국장군은 각 -3.7 g 및 -0.8 g으로 유의하게 감소되었고, 식이섭취량 및 식이효율은 대조군에 비하여 청국장군들이 유의하게 감소되었다. 간과 부고환지방의 무게 및 간조직의 콜레스테롤과 중성지질 농도는 대조군에 비하여 청국장군 및 상황버섯 청국장군이 유의하게 감소시키는 효과가 나타났다. 혈청의 중성지질, 총 콜레스테롤, LDL-콜레스테롤, VLDL-콜레스테롤 농도 및 동맥경화지수는 대조군에 비해 청국장군 및 상황버섯 청국장군이 유의하게 감소되었다. 총 콜레스테롤에 대한 HDL-콜레스테롤의 비율은 대조군에 비해 청국장군들이 유의하게 증가되었다. 변의 무게, 총 지질, 중성지질 및 콜레스테롤 배설량은 청국장군들이 대조군보다 유의하게 증가된 것으로 나타났다. 이상의 결과로 보아 고지방식이에 청국장 및 상황버섯청국장 분말을 첨가 섭취시 혈청과 간조직의 중성지질, 총콜레스테롤과 LDL-콜레스테롤 농도 및 동맥 경화지수를 낮추고, 총 콜레스테롤에 대한 HDL-콜레스테롤의 비율을 증가시키는 지질대사의 개선 효과가 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권1호
• /
• pp.148-156
• /
• 2020

Objective: This study aimed to evaluate the effect of dietary integration with extruded linseed (EL) on fatty acid (FA) and aromatic profile of goat cheese after 60 (T₆₀) days of ripening. Methods: Thirty goats were divided in two groups. The control group (CG) was fed with conventional diet, whereas the experimental group (EL+) was fed with conventional diet supplemented with 10% of EL. Milk samples were collected on 30 and 60 days of trial to determinate chemical-nutritional composition and FA profile. At the end of experiment, six cheese-making sessions (3 for each group) were carried out using a pooled milk sample obtained from the 15 goats of each group. At 60 days of ripening, cheeses were analyzed for chemical-nutritional composition, FA and aromatic profile. Results: An increase in the milk production, protein, fat and lactose were evidenced in the EL+ goats. Conversely, a reduction of somatic cells was observed in the EL+ compared with the CG. However, no variation was observed for urea and casein levels content in milk samples, and no changes in protein and lipid content were found for cheeses in the two experimental groups. Dietary supplementation with EL modified the FA profile of milk. There was a decrease in saturated FAs and an increase in polyunsaturated FAs. Chemical composition of T₆₀ cheese did not differ between the two groups but a different FA profile was observed. In T₆₀ cheese obtained from EL+ milk, an increase in short-chain FA and a decrease in medium and long-chain FA were observed. The EL diet led to cheeses with butanoic acid 2 times higher compared to CG cheeses. Moreover, a greater presence of aldehyde compounds and alcohols were observed in the cheeses of experimental group. Conclusion: The present study pointed out that EL supplementation may improve the chemical and physical qualities of goat milk and cheeses.