Earticle

실내마스크 착용 해제 및 거리 두기 완화에도 불구하고 비대면 서비스가 계속되어 이루어지고 있다. 특히 음·식료 품을 비롯한 농·축·수산물의 배송 수요는 증가하고 있어 이 에 부가되는 플라스틱 포장 폐기물의 양이 꾸준히 증가하 는 추세이다. 이에 따라 EU에서는 포장재 플라스틱의 사용 을 규제하려는 방향으로 움직임을 보였다. 이러한 국제 트 렌드의 흐름에 대응하여 국내 패키징 업계에서는 PLA, PBAT와 같은 생분해성 물질을 이용한 친환경 포장재 개발 연구를 활발히 진행하고 있다. 본 연구에서는 이러한 이슈 에 대응하여 국내 가로수 중 상당 비중을 차지하여 식재된 은행나무의 은행잎을 lactic acid 생산에 관한 새로운 원료 로 활용하고자 하였다. 은행잎은 cellulose, mannan, xylan 등의 다당류를 함유하고 있으며 대량의 원료를 얻을 수 있 다는 유용한 특징이 있다. 본 연구를 통해 전처리한 은행추 출부산물의 glucan은 단일 분획 공정으로는 높은 수율을 기 대하기 어렵다고 판단되어지며, 낮은 수욜 문제를 해결하기 위해서는 전처리 가수분해액, 효소당화액을 모두 활용하는 통합 공정이 필수적으로 적용되어야 한다.

Despite the easing of social distancing, demand for non-face-to-face services continues to rise. Recently, the EU is pursuing a comprehensive plastic use reduction by expanding the scope of plastic use regulations for packaging plastics according to the New Cyclical Economy Action Plan(NCEAP). In response to this trend, the packaging industry is moving away from conventional non-degradable/petroleum-based plastics and conducting research on packaging materials using biodegradable plastics such as PLA(Poly Lactic Acid), PBAT(Poly Butylene Adipate-co-butylene Terephthalate). On the other hand, ginkgo leaves occur in large quantities in Korea and act as a cause of slip accidents and flooding. In this study, a method to utilize ginkgo biloba leaf as a new alternative biomass resource was proposed by producing lactic acid through pretreatment, enzymatic saccharification, and fermentation processes. For the efficiency of lactic acid production, a comparative analysis of lignin content from before and after browning was performed. In addition, the degree of glucan extraction was evaluated by applying a pretreatment method using three catalysts: hot water, sulfuric acid, and sodium hydroxide. It is difficult to expect high production of lactic acid with single process. Therefore, an integrated process operation using both the pretreated hydrolyzate and the residual solid enzymatic saccharification solution must necessarily be applied.

최근 전 세계적으로 코로나바이러스감염증-19(COVID-19) 의 확산됨에 따라 비대면 서비스가 성장하고 이와 동시에 플라스틱 폐기물 문제가 더욱 심화되고 있다. 동시에 탄소 중립과 지속가능한 순환경제와 같은 친환경 정책이 전 세 계적으로 추진되고 있고 친환경 제품에 대한 높은 수요로 인해 패키징 업계에서도 PLA, PBAT 등을 사용한 친환경 포장재 개발과 새로운 비즈니스 모델 창출을 시도하고 있 다. 본 연구에서는 이러한 환경적 이슈에 우리나라 남해와 제주도 연안에서 매년 대량으로 발생하여 여러 형태의 문 제를 야기하고 있는 구멍갈파래(Ulva australis)를 새로운 대체 에너지 원료로서 활용하고자 묽은 산 전처리, 효소 당 화, 발효 공정을 거쳐 해조류 바이오매스 유래 Lactic acid 를 생산하고자 하였다. 일반적으로 해조류는 종, 수확장소, 시기 등에 따라 탄수화물의 함량과 당의 구성이 다양하며, Cellulose, Alginate, Mannan, Xylan 등의 다당류로 구성되어 있고 리그닌 성분을 함유하고 있지 않아 곡물·목질계 자원보다 유용한 특징이 있다. 구멍갈파래를 구성하고 있는 복합 다당체는 한가지 공정만으로 높은 추출 수율을 기대 하기 어려우나 본 연구에서 제시된 묽은 산 및 효소 당화 의 융합 공정은 구멍갈파래가 함유하고 있는 대부분의 당 추출이 가능하기 때문에 상업화 규모의 생산 공정 구축 시 높은 Lactic acid 생산 수율을 기대할 수 있을 것으로 사료된다.

With the spread of COVID-19 worldwide, non-face-to-face services have grown rapidly, but at the same time, the problem of plastic waste is getting worse. Accordingly, eco-friendly policies such as carbon neutrality and sustainable circular economy are being promoted worldwide. Due to the high demand for eco-friendly products, the packaging industry is trying to develop eco-friendly packaging materials using PLA and PBAT and create new business models. On the other hand, Ulva australis occurs in large quantities in the southern seas of Korea and off the coast of Jeju Island, causing marine environmental problems. In this study, lactic acid was produced through dilute acid pretreatment, enzymatic saccharification, and fermentation processes to utilize Ulva australis as a new alternative energy raw material. In general, seaweeds vary in carbohydrate content and sugar composition depending on the species, harvest location, and time. Seaweed is mainly composed of polysaccharides such as cellulose, alginate, mannan, and xylan, but does not contain lignin. It is difficult to expect high extraction yield of the complex polysaccharide constituting Ulva australis with only one process. However, the fusion process of dilute acid and enzymatic saccharification presented in this study can extract most of the sugars contained in Ulva australis. Therefore, the fusion process is considered to be able to expect high lactic acid production yield when a commercial-scale production process is established.

A galactose fermentation bacterium producing lactose from red seaweed, which was known well to compromise the galactose as main reducing sugar, was isolated from button mushroom bed in Buyeo-Gun, Chungchugnamdo province. The lactic acid bacteria MONGB-2 was identified as Lactobacillus paracasei subsp. tolerans by analysis of 16S rRNA gene sequence. When the production of lactic acid and acetic acid by L. paracasei MONGB-2 was investigated by HPLC analysis with various carbohydrates, the strain MONGB-2 efficiently convert the glucose and galactose to lactic acid with the yield of 18.86 g/L and 18.23 g/L, respectively and the ratio of lactic acid to total organic acids was 1.0 and 0.91 g/g for both substrates. However, in the case of acetic acid fermentation, other carbohydrates besides galactose and red seaweed hydrolysate could not be totally utilized as carbon sources for acetic acid production by the strain. The lactic acid production from glucose and galactose in the fermentation time courses was gradually enhanced upto 60 h fermentation and the maximal concentration reached to be 16-18 g/L from both substrates after 48 h of fermentation. The initial concentration of glucose and galactose were completely consumed within 36 h of fermentation, of which the growth of cell also was maximum level. In addition, the bioconversion of lactic acid from the red seaweed hydrolysate by L. paracasei MONGB-2 appeared to be about 20% levels of the initial substrates concentration and this results were entirely lower than those of galactose and glucose showed about 60% of conversion. The apparent results showed that L. paracasei MONGB-2 could produce the lactic acid with glucose as well as galactose by the homofermentation through EMP pathway

본 연구의 목적은 20~30대 남성을 대상으로 지연성 근통증 유발 프로그램 후 크라이오테라피에 적용이 혈중 젖산 과 암모니아와 같은 피로물질, 젖산탈수소효소와 크레아틴키나아제와 같은 근손상지표, 그리고 통증에 미치는 효과를 검증하는데 있다. 연구대상자는 20~30대 남성으로 18명의 대상자를 크라이오테라피를 적용하는 실험군(EG, n=9), 그리고 적용하지 않는 대조군(CG, n=9)으로 무작위 대조방법을 통해 할당하였다. 모든 연구 대상자들은 실험실에 도착 해 DOMS 유발 프로그램을 시행하였으며, 프로그램 시행 후 EG는 3분간 크라이오테라피를 적용하였다. 연구의 1차 결과 는 혈액변인으로 젖산, 암모니아, 젖산탈수소효소, 그리고 크레아틴키나아제를 평가하였고 2차 결과로 통각계를 통해 통증을 평가하였다. 연구 결과는 젖산과 암모니아에서 상호작용 효과를 확인하였고 젖산탈수소효소와 통증은 CG에서 증가한 반면 EG에서는 억제되는 것을 확인하였다. 결론적으로 지연성 근통증을 유발하는 운동 후 크라이오테라피의 적용 은 젖산, 암모니아, 그리고 젖산탈수소효소의 증가를 억제하며, 통증을 개선하는 것을 본 연구를 통해 증명하였다.

The purpose of this study was to investigate the effects of cryotherapy on men in their 20s and 30s after a delayed onset muscle soreness(DOMS) induced program on fatigue substances such as lactic acid and ammonia in the blood, muscle damage indicators such as lactate dehydrogenase(LDH) and creatine kinase(CK), and pain. The study participants were males in their 20s and 30s, and 18 parti0cipants were randomly assigned to the experimental group(EG, n=9) to which cryotherapy was applied and the control group to which it was not applied (CG, n=9) through a randomized control method. All study participants arrived at the laboratory and were performed to a DOMS induction program. After the program, EG applied cryotherapy for 3 minutes. The primary outcome of the study was the evaluation of lactate, ammonia, LDH, and CK as blood variables, and the secondary outcome was the evaluation of pain through a digital algometer. The results of the study confirmed the interaction effect of lactic acid and ammonia, and it was confirmed that LDH and pain were increased in CG while suppressed in EG. In conclusion, this study proved that the application of cryotherapy after exercise that induces DOMS inhibits the increase in lactate, ammonia, and lactate dehydrogenase, and improves pain.

Oxygen is an essential element for animal life. Although deaths due to lack of oxygen occur frequently under various indoor conditions, verifying hypoxia as the cause of mortality has remained elusive. Also, the biomarkers indicating the hypoxia-induced death have not yet been clearly identified. In this study, we screened potential metabolites of which levels in animal blood can be differentiated under hypoxic conditions. Metabolites of post-mortem bloods exposed to various low-oxygen levels (3%, 5%, 8% and 12%) were compared with those from mice ambient air. GC/MS analysis showed increase in levels of lactic acid, succinic acid, uric acid and uracil in post-mortem blood from mice exposed to moderately low oxygen level (12%). Whereas samples from mice in much lower oxygen level (3% and 5%) did not show significant differences in metabolites levels. Importantly, the increase rate of these metabolites appeared to be proportional to survival time after hypoxia, suggesting that there are hypoxia-inducible cell responses including the avoidance of oxygen-dependent energetic metabolism. The results suggest that both oxygen concentration and duration exposed to hypoxia condition determine cellular metabolic pathways to increase their consequent metabolites in animal fluids, which may be used as biomarkers for tracking hypoxia.

목적: 본 연구는 Lactobacillus plantarum J2K-27 (L. Plantarum J2K-27) 유산균을 발효한 폴리하이드록시산(PHA)의 변화를 분 석하고 그 효능을 통해 화장품 소재로서 가능성을 확인해보았다. 방법: L. Plantarum J2K-27 균주를 이용한 PHA의 발효에 의한 성분변화를 확인하고자 고성능 액체 크로마토그래피(HPLC) 분석을 진행하였다. 발효된 PHA의 항산화 효능 및 세포생존율을 측 정하고 히알루론산 및 프로콜라겐 type 1 생성량 측정을 통해 화장품 소재로 가능성을 확인하였다. 결과: HPLC 분석 결과, 발효된 PHA는 락토바이오닉산(lactobionic acid)과 젖산(lactic acid)의 성분을 생성하는 것을 확인할 수 있었다. 또한, 발효된 PHA는 농도 의존적으로 항산화 효과를 나타내었으며, 세포 독성이 없는 농도에서 프로콜라겐 및 히알루론산의 생성량이 농도 의존적으로 증가 하는 것이 확인 되었다. 결론: 본 연구 결과를 종합하여, L. Plantarum J2K-27 균주를 이용한 PHA는 lactobionic acid과 lactic acid 의 성분을 생성하면서 기능성 화장품 소재로서 가능성이 있음을 확인하였다

Purpose: This study aimed to investigate the characteristics of fermented poly hydroxyl acid (F-PHA) using the Lactobacillus plantarum J2K-27 strain, and identify the applicability of its biological compounds. Methods: F-PHA was analyzed using high-performance liquid chromatography (HPLC) to identify its active compounds. Furthermore, the radical scavenging activities were evaluated for F-PHA. The cell viability and expression of procollagen type 1 and hyaluronic acid were investigated. Results: Changes in F-PHA represented the increase of lactobionic acid and lactic acid after fermentation. F-PHA increased radical scavenging activity in a dosedependent manner. After fermentation, F-PHA was confirmed to increase the expression of procollagen type 1 synthesis and hyaluronic acid without cytotoxicity. Conclusion: These results confirmed that F-PHA shows generally higher activities functional cosmetic material.

目的: 本研究旨在研究植物乳杆菌J2K-27菌株的发酵多羟基酸(F-PHA)的特性，并确定其生物化合物的适用性。 方法: 使用高效液相色谱(HPLC)分析F-PHA，以确定其活性化合物。此外，测量了发酵的PHA的抗氧化功效和细 胞活力，并且通过测量所产生的透明质酸和1型胶原原的量来确认了作为化妆品材料的潜力。结果: HPLC分析的 结果，证实了发酵的PHA产生了乳糖酸和乳酸的组分。另外，发酵的PHA以浓度依赖性方式显示抗氧化作用， 并且证实了在没有细胞毒性的浓度下前胶原蛋白和透明质酸的产生量以浓度依赖性方式增加。结论: 这些结果证 实了使用L.Plantarum J2K-27菌株的PHA在生产乳糖酸和乳酸的组分方面具有作为功能性化妆品材料的潜力。

본 연구의 목적은 축구 경기 후 냉수침수와 온수침수 처치를 통해 생리적 요인에 미치는 효과를 규명하는데 있다. 이를 위해 M대학축구선수 20명을 대상으로 냉수침수군(7명), 온수침수군(7명), 일반 휴식군(6명) 세 그룹으로 구분하 여 대상자를 선정하였다. 본 연구의 실험은 냉수침수군, 온수침수군, 일반 휴식군을 균등하게 두 팀으로 나누어 연습경기 를 진행하였고, 연습경기는 전반 45분, 하프타임 15분, 후반 45분을 진행하였다. 생리적 요인의 변화를 측정하기 위해 시합 시작 2시간 전, 시합 종료 직후, 냉수, 온수, 일반 휴식 처치 후 등 총 3회에 걸쳐 채혈을 진행하였다. 혈액 표본을 이용해 생리적 요인(젖산, 암모니아, CK, LDH, IgG, 백혈구)을 분석하여 다음과 같은 결론을 얻었다. 젖산, 암모니아, CK는 온수침수 처치 유형이 가장 회복 효과가 높게 나타났고, LDH, IgG, 백혈구는 냉수침수 처치 유형이 가장 회복 효과 가 높은 것으로 나타났다. 따라서 축구 경기 후 피로 회복이 목적일 경우에는 온수 침수 처치가 적합하고, 근 손상, 면역력 하락에 의한 회복이 목적일 경우에는 냉수 침수가 적합한 것으로 판단된다.

The purpose of this study was to investigate the effects of cold water immersion and hot water immersion treatment on the physiological factors after the soccer game for university elite soccer players. University soccer players were divided into cold water immersion group(n = 7), hot water immersion group(n = 7) and general rest group(n = 6). The experiment was divided into cold water immersion group, hot water submersion group and general rest group. The training session was 45 minutes in total, 15 minutes in half time, and 45 minutes in the second half. In order to measure changes in physiological factors, blood sampling was carried out three times, two hours before the start of the game, immediately after the game, after cold water, hot water, and after a general relaxation treatment. The following conclusions were obtained by analyzing physiological factors(lactic acid, ammonia, CK, LDH, IgG, white blood cells). The results of this study showed that the most effective recovery of lactic acid, ammonia, and CK was achieved by the type of hot water immersion treatment, while the LDH, IgG, leukocyte. Therefore, it is considered that warm water immersion treatment was suitable when fatigue recovery was aimed after football game, and cold water immersion was appropriate when muscle injury and recovery by immune reduction were aimed.

Training methods for Paralympic swimmers must take into account dif-ferent pathologies, competitions classes, athlete’s individual circum-stances and peculiar physical adaptation mechanisms, hence general guidelines cannot be found in literature. In this study we present a training program, implemented for the physical preparation of a top lev-el Paralympic swimmer. The athlete under study, affected by infantile cerebral palsy within a clinical picture of a spastic tetraparesis, by the end of 2016 was holder of Italian, European, world and Paralympic titles in the 400-m freestyle competition, S6 class. The training macrocycle was structured in a 3-fold periodization (three mesocycles), in view of the preparation to three international competitions. The 4-month train-ing mesocycles prior to each competition differed substantially in terms of mileage load, intensity and recovery times. The first mesocycle was characterized by a sizeable low-intensity mileage load, the second one was shifted to lower mileage load, carried out at middle-to-high intensi-ty levels, the third one entailed increased effort intensity, counterbal-anced by lower mileage load. In all cases, recovery times were bal-anced to obtain optimized performance through physical adaptation to training stimuli, keeping into account the physiopatological response. Tapering phases were adjusted to maximize performance at competi-tion. As an assessment of the effectiveness of the training method, cor-respondence between chronometric and technical parameters in the three competitions and the respective mesocycle training programs was found. The results of the present study may support the develop-ment of training guidelines for athletes affected by upper motor neuron lesions.

The shoulder is susceptible to disturbances caused by microtraumas due to direct contact of the surrounding skeletal structures or failure of the soft parts of the rotator cuff and other muscles inserted into the gle-nohumeral joint. The purpose of the study was to compare the electro-myographic signal in the stabilizing muscles of the shoulder during the diagonal elevation exercise as recommended by the proprioceptive neuromuscular facilitation (PNF) method and dumbbell exercise. This study is classified as Quase-experiment. Subjects were instructed to perform diagonal standard exercises and the electromyographic signal was detected from pectoralis muscles, middle and upper trapezius of dominant limb in each subject. We observed greater muscular recruit-ment when the PNF method was adopted in comparison with the dumbbell workouts for the trapezius upper and middle fiber muscles and for the major pectoralis (267,30 μv/181,02 μv; 235,76 μv/;164,47 μv; 299,87 μv/148,69 μv; P<0.001). The PNF method promotes a greater re-cruitment of the shoulder dynamic stabilizing muscles during diagonal elevation exercises. Being so, such kinesiotherapeutic technique may be effectively used in the prevention, treatment and rehabilitation of shoulder disorders.

This study was conducted to evaluate effects of supplementation of Bifidobacterium ruminantium on in vitro ruminal fermentation and methane production. Ruminal fermentation characteristics of Timothy hay (C1), whole barley (C2), Timothy hay + B. ruminantium (T1) and whole barley + B. ruminantium (T2) were evaluated at 0, 3, 6, 9, 12, 24 and 48 h incubation at 39℃. The amount of B. ruminantium culture added into T1 and T2 was 0.3 ml. The pH values ranged from 5.99 to 6.83 in all the treatments. Concentration of NH3-N of C2 and T2 was higher than C1 and T1 at 48 h (p<0.05). The total gas production of C2 and T2 was higher than C1 and T1 at 9 h (p<0.05). The total methane production of treatments with B. ruminantium was not significantly different at 24 and 48 h (p<0.05). Concentration of lactic acid was significantly different between both substrates (p<0.05). Therefore, B. ruminantium supplementation was determined to be insignificant in the in vitro ruminal fermentation and methane production, while a further study was required to investigate relation to lactic acid production with different forage sources.

The purpose of this study was investigate effects of power walking exercise program after caffeine intake in rehabilitation treatment of female obese. The subjects were divided into caffeine intake and power walking group(n＝10) & power walking group(n＝10) for 10 weeks. The changes of FFA, Glucose, Lactic acid have been measured before and after 10 weeks. The results of this study were as follows: First, the FFA was significantly decreased difference within both in caffeine group(caffeine intake and power walking rehabilitation program group) and control group(power walking group) after 10 weeks. And there was significantly different between two groups. Second the Glucose was no significantly different within in caffeine group(caffeine intake and power walking rehabilitation program group), but control group(power walking group) was significantly different within in after 10 weeks. And there was no significantly difference between two groups. Third, the Lactic acid was significantly increased within in caffeine group(caffeine intake and power walking rehabilitation program group) but control group(power walking group) was no significantly different within in after 10 weeks. And there were significantly difference between two groups.

본 실험은 오리 가슴육의 저장성 향상에 대안을 마련하고자 차염소산나트륨 20, 50ppm, lactic acid와 acetic acid를 각각 1, 2%를 분무 살포한 후 진공포장지로 포장하여 4℃에서 7일간 저장을 하면서, 소독제 및 유기산 처리에 따른 오리육의 육색, 저장특성 및 미생물 증식에 대하여 조사하였다. 오리육의 차염소산나트륨 20～50ppm 및 유기산(lactic acid, acetic acid)을 1～2% 처리 후 1일이 경과했을 때 pH는 5.83～5.87로 처리 간에 큰 차이가 없었고, 저장기간에 따라서는 저장 3일까지 증가하는 경향을 나타내다 점차 감소하였다. 지방산패도(TBARS)는 저장기간이 경과함에 따라 차염소산나트륨 처리구보다 유기산 처리구(lactic acid와 acetic acid)에서 감소하는 경향이 크게 나타났으며, 특히 acetic acid 2% 처리구에서 감소율이 컸다. 비 단백질태 질소화합물(VBN)은 저장기간이 경과할수록 증가하였으나, 차염소산나트륨 및 유기산의 종류와 처리 수준에 따라서는 큰 차이를 나타내지 않았다. 육색 변화는 lactic acid 2% 처리 구에서 적색도(a*) 및 황색도(b*)가 약간씩 감소하는 경향을 나타내었다. 소독제 및 유기산 처리에 따른 총 미생물 수는 저장기간이 경과할수록 증가하는 경향을 나타냈으나, 유기산 처리구 중 acetic acid 처리구가 저장 기간 중 미생물 증가율이 가장 낮았으며, 특히 acetic acid 2% 처리 구에서 낮은 증가율을 나타내었다.

This study was performed to extend the shelf-life of duck breast treated with NaCIO(20, 50ppm), lactic acid(1, 2%) and acetic acid(1, 2%). Changes in microbial counts, storage characteristics and color values of duck breasts were determined during storage at 4℃ for 7 days. Although pH values were not different on the first day of storage. they increased up to 3rd days of storage and decreased gradually thereafter. Thiobarbituric acid reactive substances(TBARS) of duck breasts treated with lactic acid and acetic acids were lower TBARS than those with lactic acid on the 7th days of storage. Volatile basic nitrogen(VBN) didn't differ among the treatments(P>0.05). Although the microbial counts were increased in all treatments, acetic acid treatment had lower microbial counts among the treatments during storage. These results indicated that acetic acid would be the best treatment to extend the shelf-life of duck breasts among others.

To improve the fermentation quality of silage and reduce the nutrients loss of raw materials during the ensiling process, silage additives are widely used. The effect of additives on silage is also affected by the species of crop. Therefore, this study was designed to explore the effects of formic acid (FA) and lactic acid bacterial inoculant on the quality of main summer crop silage. The experiment was consisted on split-plot design with three replications. The experiment used the main summer forage crops of proso millet (“Geumsilchal”), silage corn (“Gwangpyeongok”), and a sorghum-sudangrass hybrid (“Turbo-gold”). Treatments included silage with Lactic acid bacterial Inoculant (Lactobacillus plantarum [LP], 1.0 × 106 CFU/g fresh matter), with FA (98%, 5 mL/kg), and a control (C, without additive). All silages were stored for 60 days after preparation. All additives significantly increased the crude protein content and in vitro dry matter digestibility (IVDMD) of the silages and also reduced the content of ammonia nitrogen (NH3-N) and pH. Corn had the highest content of IVDMD, total digestible nutrients and relative feed value among silages. Compared with the control, irrespective of whether FA or LP was added, the water soluble carbohydrate (WSC) of three crops was largely preserved and the WSC content in the proso millet treated with FA was the highest. The treatment of LP significantly increased the lactic acid content of the all silage, while the use of FA significantly increased the content of acetic acid (p < 0.05). The highest count of lactic acid bacteria (LAB) was detected in the LP treatment of corn. In all FA treatment groups, the total microorganism and mold numbers were significantly lower than those of the control and LP groups (p < 0.05). In conclusion, both additives improved the fermentation quality and nutritional composition of the main summer forage crops. The application of FA effectively inhibited the fermentation of the three crops, whereas LAB promoted fermentation. So, both FA and LP can improve the quality of various species of silage.

PLA와 nanoclay인 Nanomer® I.44P를 이용한 환경 친 화적인 nanocomposites을 개발하였다. PLA/Nanomer® I.44P nanocomposites의 상온 건조 후 잔존하는 용매를 제 거하기 위해 진공건조를 하였으며, 진공건조 시간이 8시간 까지는 신장율이 크게 감소하였으며, 그 이후에는 유의적인 차이가 없었다. Nanoclay가 PLA matrix내에서 균일하게 분산시키기 위해 초음파 처리를 하였으며, 초음파 처리시간 이 5분까지는 인장강도 및 영모듈러스가 증가하는 경향을 보였으나 5분 이상의 초음파 처리에서는 시간이 증가함에 따라 인장 특성도 점차 감소하였고, 특히 15분 이상 초음 파 처리를 하였을 때에는 nanoclay가 뭉치는 현상이 관찰 되었다. Nanoclay의 양이 증가할수록 nanocomposites의 가 시광선 영역에서의 투과성(trasmittance)은 62.5%에서 7.8% 로 크게 감소하였다. Water vapor permeability (WVP)는 nanoclay의 첨가량에 따라 감소하는 경향을 보이며, 5%의 nanoclay 첨가 시 3.5×10-11g·m/m2·s·Pa로 control에 비해 약 43%가 감소하였다.

Biodegradable nanocomposites were fabricated with poly (lactic acid) (PLA) and Nanomer® I.44P using ultrasonication (US). Processing conditions were optimized to obtain the maximum tensile properties of the nanocomposites. Poly (ethylene glycol) (PEG) was used as a plasticizer to avoid the brittleness of nanocompsoties. In order to disperse nanoclay into the PLA matrix, PEG and Nanomer® I.44P were firstly mixed and dispersed in the chloroform and followed by ultrasonication for 1 min With 10% PEG 400, tensile stress and Young’s modulus of the nanocomposites decreased from 53.5 MPa and 2225 MPa to 37.0 MPa and 1757 MPa, respectively, while the elongation was increased from 4% to 21%. Tensile stress, Young’s modulus, and elongation of nanocomposites were also increased with nanoclay concentration up to 2% (w/w) and were decreased with further increase in the nanoclay concentration. Transmittance of nanocomposites were significantly decreased from 62.5% for pure PLA film to 7.8% for 5% nanoclay containing nanocomposites. Water vapor permeability of the nanocomposites was also significantly decreased with nanoclay concentration and the minimum WVP of 3.5×10-11g·m/m2·s·Pa was obtained with 5% (w/w) nanoclay concentration. The PLA/Nanomer® I.44P nanocomposites showed a great potential as a environmental friendly food packaging material.

Fermented vegetables are globally appreciated for their distinctive flavors and advantageous health effects. Fermentation enhances the nutritive quality, flavor, and lifespan of food products. Fermented vegetable flavor profiles are intricately linked to microbiota assessment and progression. Flavor primarily consists of taste, aroma, tactile and temperature factors. Several metabolic pathways produce flavor-active compounds from precursors found in the raw materials. This review assesses the role of lactic acid bacteria in influencing metabolic pathways, including lipid metabolism, as well as carbohydrate and amino acid metabolism, which are responsible for producing aromatic compounds that contribute to flavor formation in fermented vegetables. Moreover, the review highlights key factors (temperature, pH, salts levels, oxygen availability and substrate availability) that affect flavor formation, and explores flavor profile of popular Chinese fermented vegetable products, such as Sauerkraut, Sichuan paocai, Dongbei suancai, and Jiangxi yancai that are widely consumed in.

This study was conducted to isolate and identify the lactic acid bacteria(LAB) from spent mushroom substrates(SMS) for the effective anaerobic fermentation to utilize SMS as an animal feed and to determine the optimal medium conditions for their growth. At first, a total of 23 strains were isolated from the ensiled SMS based on the LAB counts and pH tested. Then, a total of 16 strains which rapidly produce lactate and decreased the pH, were selected for a screening test. The optical density(OD), pH, and yellow clear zone were tested for the selected 16 strains. Among the strains, KU5 strain had wider yellow clear zone and lower pH and KU13 strain had higher OD at 24 hr of incubation and wider yellow clear zone compared to other strains and control strain(Lactobacillus plantarum KCCM 12116). Accordingly, KU5 and KU13 strains were finally selected. The KU5 and KU13 were identified as Lactobacillus plantarum by the 16S rRNA sequencing. The KU5 strain was named as Lactobacillus plantarum KU5, and the KU13 strain was named as Lactobacillus plantarum KU13. Lactobacillus plantarum KU5 and Lactobacillus plantarum KU13 were registered at the National Center for Biotechnology Information(NCBI). Access number of Lactobacillus plantarum KU5 was HQ542227 and that of Lactobacillus plantarum KU13 was HQ542228. The optimal medium conditions for growth of KU5 and KU13 were soybean meal 2% and formulated feed 2%, respectively.

Kahudi or Pani tenga is a very unique fermented mustard product of Assam that is prepared by mixing coarsely ground mustard with extracts of acidic Garcinia pedunculata (Thekera) or tamarind. Kahudi is produced through a spontaneous and uncontrolled solid state fermentation and very little scientific effort has been directed to understand its microflora and their functional properties. In this paper, we report the microbial flora and their dynamics during Kahudi fermentation with special emphasis on lactic acid bacteria (LAB). LAB were found to be dominant (8 log CFU/g) over other microbial flora (4 log CFU/g) during the fermentation process leading to Kahudi formation. The microbial load in Kahudi did not include any mycelial molds or pathogenic enteric bacteria. Combination of phenotypic parameters, biochemical tests, and 16S rDNA gene sequencing revealed the dominant group of LAB as Enterococcus durans, Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus casei. The sugar fermentation and enzyme profile analysis revealed the ability of the microbial consortia to metabolize an array of indigestible sugars including D-mannose, mannitol, sorbitol, methyl-α-D-mannopyranoside, methyl-α-D-glucopyranoside, N-acetylglucosamine, amygdalin, and arbutin. Although the isolates showed good acid phosphatase activity they had weak extracellular phytase activity. This is the first report on the microbial dynamics and involvement of LAB during Kahudi fermentation.

Constipation, which refers to difficulties in defecation and infrequent bowel movement in emptying the gastrointestinal system that ultimately produces hardened fecal matters, is a health concern in livestock and aging animals. The present study aimed to evaluate the potential effects of dairy-isolated lactic acid bacteria (LAB) strains to alleviate constipation as an alternative therapeutic intervention for constipation treatment in the aging model. Rats were aged via daily subcutaneous injection of D-galactose (600 mg/body weight [kg]), prior to induction of constipation via oral administration of loperamide hydrochloride (5 mg/body weight [kg]). LAB strains (L. fermentum USM 4189 or L. plantarum USM 4187) were administered daily via oral gavage (1 × 10 Log CFU/day) while the control group received sterile saline. Aged rats as shown with shorter telomere lengths exhibited increased fecal bulk and soften fecal upon administration of LAB strains amid constipation as observed using the Bristol Stool Chart, accompanied by a higher fecal moisture content as compared to the control (p < 0.05). Fecal water-soluble metabolite profiles showed a reduced concentration of threonine upon administration of LAB strains compared to the control (p < 0.05). Histopathological analysis also showed that the administration of LAB strains contributed to a higher colonic goblet cell count as compared to the control (p < 0.05). The present study illustrates the potential of dairy-sourced LAB strains as probiotics to ameliorate the adverse effect of constipation amid aging, and as a potential dietary intervention strategy for dairy foods including yogurt and cheese.