• Preventive Nutrition and Food Science
• /
• 제2권4호
• /
• pp.296-300
• /
• 1997

Glucose syrup and lactose, mixed with citric acid as a polymerizing catalyst, was processed using twin screw extruder, in which 40 of L/D(length/diameter) ratio was designed to provide sufficient retention in extruder for polymerization of sugars. The polymerization yields of glucose syrup were 36.90%, 55.44% and 77.10% at 160, 180 and 20$0^{\circ}C$, respectively, while those of lactose were 26.45%, 38.16% and 45.86% at the same temperatures. Gel permeation chromatography exhibited that the higher molecular weight fractions were increased with extrusion temperature, which also led to increasing hydrodynamic intrinsic viscosity. Both uco-oligosaccharides and lacto-oligosaccharides produced by extrusion of glucose syrup and lactose were stable for thermal treatments over a wide range of pH3.0~11.0. In addition, $\alpha$-amylase and amyloglucosidase treatment of gluco-oligosaccharides did not affect the solution viscosity, indicating the random linkage rather than $\alpha$-1, 4 linkages of glucose and thus the potential applications as a dietary fiber. In this research it was clearly observed that twin screw extrusion can be successfully utilized to produce gluco-oligosaccharides and lacto-oligosaccharides rapidly and continuously in conjunction with selective control of polymerized composition.

• KSBB Journal
• /
• 제16권5호
• /
• pp.459-465
• /
• 2001

본 연구에서는 생물공정에서 주요 기질로 이용되는 글루코오스와 전분을 온라인 모니터링 하기 이하여 GOD, AMG를 이용한 흐름 주입분석(Flow Injection Analysis : FIA) 기술을 개발하였고, 효소활성 변화를 비교, 고찰하였다. 특히, epoxy 고분자 담체에 고정화된 COD-FIA와 AMG/GOD-FIA 장치의 성능을 조사하였고, FIA의 조작온도, pH, 운반용액의 첨가제, 염 그리고 각종 신진대사물질의 고정화된 GOD, AMG의 활성에 대한 영향을 소형 반응기내 글루코오스와 전분의 농도 변화를 온라인 모니터링하였다. GOD-FIA에 의한 온라인 모니터링 결과는 오프라인 분석과 비교적 잘 일치하였으며, AMG/GOD-FIA에의한 전분 농도의 온라인 모니터링은 단일 효소 반응기를 사용한 경우 두 개의 효소 반응기를 사용한 경우보다 더 효과적임을 알 수 있었다.

• Food Science and Biotechnology
• /
• 제16권3호
• /
• pp.381-385
• /
• 2007

The objective of this experiment was to study the influence of feed moisture content on the degree of enzymatic hydrolysis of com starch in a twin screw extruder and the saccharification yield of the dried extrudate. The feed moisture content was set at 25, 30, and 35% and ${\alpha}$-amylase solution was directly injected into the feed section at a barrel temperature of $95^{\circ}C$ and screw speed of 250 rpm. Amyloglucosidase was used for the saccharification of the dried extrudate at a concentration of 0.055%(w/w). Expansion ratio and swelling factor of extrudates decreased with increasing the feed moisture content. Addition of ${\alpha}$-amylase during extrusion process raised reducing sugar content of extrudates which also increased with the feed moisture content. The saccharification yield of dried extrudate was higher for the extrudate with lower feed moisture content.

• Journal of Microbiology and Biotechnology
• /
• 제8권6호
• /
• pp.588-594
• /
• 1998

Lactic acid bacteria were isolated from Kimchi and screened for bacteriocin production. Strain SE1, identified as Lactobacillus curvatus sp., showed the strongest inhibitory activity against Lactobacillus delbrueckii subsp. delbrueckii. The bacteriocin was inactivated by amyloglucosidase, trypsin, or protease K treatment. However, it maintained its activity under heat treatment at $100^{\circ}C$ for 60 min. The production of the bacteriocin had a growth-related mode and decreased around the early-stationary phase. The optimum temperature for the growth of L. curvatus SE1 was $37^{\circ}C$; however, the optimum temperature for bacteriocin production was $30^{\circ}C$. The bacteriocin activity was decreased by treatment with methanol, butanol, acetone, or chloroform, however, it was not affected by treatment with ethanol, iso-propanol, or cyclohexane. The inhibitory activity of bacteriocin was stable over a wide range of pHs (2 to 11). The bacteriocin from L. curvatus SE1 killed the indicator strain by a bactericidal mode of action. The bacteriocin from L. curvatus SE1 was partially purified by ethanol precipitation and ion exchange chromatography. SDS-polyacrylamide gel electrophoresis was used to determine the molecular weight of the bacteriocin by the bacteriocin activity test. The apparent molecular mass of the bacteriocin produced by L. curvatus SE1 was about 14 kDa.

• 한국미생물·생명공학회지
• /
• 제19권1호
• /
• pp.8-13
• /
• 1991

원유로부터 bacteriocin을 생산하는 미생물을 분리하고 이 균주들을 중심으로 Lactobacillus plantarum을 target organism으로 하여 항균력을 비교하였다. 분리된 항균성물질들은 Gram양성 및 음성균에 대하여 넓은 항균 spectrum을 보였으며 선발균주 중 최종적으로 항균력이 가장 높은 1112-1을 우량균주로 선발하였다. 선발한 1112-2 균주의 항균성물질 230 IU/ml 첨가시에 Lactobacillus plantarum의 생육은 완전히 억제되었으며 500IU/ml 첨가시 E.coli의 생육은 대조구조에 비하여 11 억제되었다.

• Preventive Nutrition and Food Science
• /
• 제11권4호
• /
• pp.318-322
• /
• 2006

The objective of this experiment was to investigate the effect of extrusion of ginseng roots in twin screw extruder on susceptibility of ginseng starch toward hydrolysis by ${\alpha}-amylase$ BAN 480L (Novozyme, Denmark) and cellulase Celluclast 150L and saccharification by amyloglucosidase AMG-E (Novozyme, Denmark). The extrusion was conducted at 22% and 30% moisture contents of feed at screw speed 300 rpm. Barrel temperature at zone 1 was adjusted at $100^{\circ}C$ and $120^{\circ}C$. The results showed that extrusion process improved the ginseng ${\alpha}-amylase$ susceptibility as compared to traditionally dried ginseng (white and red ginseng). Reducing sugar of hydrolyzed extruded samples was 2,500% of its initial concentration, whereas the reducing sugar of hydrolyzed non-extruded sample was only 200% of its initial concentration. However, addition of cellulase during liquefaction lowered the saccharification yield of both non-extruded and extruded samples as well.

• KSBB Journal
• /
• 제5권4호
• /
• pp.335-339
• /
• 1990

전분으로 부터 에탄올을 생산하기 위한 경제적인 공정을 개발하기 위하여 Zymomonas mobilis와 당화효소(AMG)를 사용한 반 회분식 동시 당화 발효공정올 연구 하였다. 응집성 에탄올 균주인 Z. mobilis ZM40l과 침전조를 사용한 균체 재순환 방식에 의한 반회분식 동시 당화발효 공정에서는 에탄올 생산성이 제2차 및 제3차 발효에서 각각 4.1g / I / h 및 4.3 g / I / h이었다. 이에 비해 미세여과막(microfiltration) 장치에 의한 Z. mobilis ZM4의 재순환 방식을 사용하는 공정에서는 에탄올 생산성이 제2차 및 제3차 발효에서 모두 5.4 g / l / h로 더 높았다. 에탄올 생산 시설이 large-seale임을 고려할 때 미세여과막을 사용하는 반회분식 공정이 에탄올 생산성과 seale-up의 용이성 및 운전의 간편성등의 관점에서 가장 개발 가능성이 높은 공정인 것으로 판단되었다.

• 한국작물학회지
• /
• 제57권3호
• /
• pp.226-232
• /
• 2012

Through the sampling four rice cultivars with differing amylose contents, the relationship between the structural and gelatinization properties of endosperm starches was analyzed. These rice varieties exhibited different chain length distribution ratio within the amylopectin cluster as well as varing amylose levels. The proportion of amylopectin short chains of in Goami cutlivars was higher than the other varieties, whereas the Goami 2 which shows amylose extender mutant properties in the endosperm showed the highest proportion of long chains. In X-ray diffraction analysis of rice starches, the Goami 2 variety displayed a B-type pattern whereas the other varieties were all A-type. Among the cultivars with high and normal rice starch levels, those with the higher amylose contents showed distinctly lower swelling. Goami 2 rice was found to have the highest onset and peak gelatinization temperature from the differential scanning calorimetry results. The four rice cultivars under analysis also showed different rates of hydrolysis by amyloglucosidase. These findings suggest that the composition and chemical structure of the starch content is a major determinant of both the gelatinization and functional properties of rice.

• KSBB Journal
• /
• 제26권5호
• /
• pp.400-406
• /
• 2011

This study was investigated to improve the saccharification yield of Ulva pertusa Kjellman by the high pressure homogenization process. It was found that the high pressure homogenization pretreatment effectively destructed the cell wall structures only by using water. The high pressure homogenization process was operated under various conditions such as 10000, 20000 or 30000 psi with different recycling numbers. The optimal condition was determined as 30000 psi and 2 pass of recycling numbers and the sugar conversion yields were 16.02 (%, w/w) of glucose and 14.70 (%,w/w) of xylose, respectively. In the case of enzymatic treating the hydrolyzates with 5 FPU/glucan of celullase and 100 units/mL of amyloglucosidase, 65.8% of carbohydrates was converted into glucose. Using the hydrolysates of Ulva pertusa Kjellman, 48.7% of ethanol was obtained in the culture S.cerevisiae. These results showed that the high pressure homogenization process could efficiently hydrolyze the marine resource by using only water for bioethanol production.

• Fisheries and Aquatic Sciences
• /
• 제24권8호
• /
• pp.284-295
• /
• 2021

Red sea cucumber Stichopus japonicus is an invertebrate animal inhabiting in coasts of Korea, China, and Japan. They are traditionally used for food and medicine and well known for their distinctive biologically and pharmacologically important compounds. We investigated the effect of amyloglucosidase (AMG) enzymatic extracts of S. japonicus (AESJ) on the proliferation and cytokine secretion of murine splenocytes stimulated with concanavalin A (Con A). AESJ enhanced the proliferation of splenocytes and the production of IL-2 (Th1 cytokine), IL-1β (Th1 promoting cytokine), and IL-4, IL-10 (Th2 type cytokines) when treated alone. However, under Con A stimulation, AESJ suppressed the proliferation of splenocytes, attenuated the secretion of IL-2, IL-4, IL-10, and enhanced IL-1β secretion. These results suggest that AESJ exhibits immunomodulatory effect by moderating the proliferation of splenocytes and the secretion of IL-2, IL-1β, IL-4, and IL-10 differently depending on the absence and presence of Con A stimulation. These data evidence the immunomodulatory potential of AESJ, which can be further developed into a functional food mediating homeostasis.