Physicochemical properties of buckwheat roasted at specified temperatures (175, 200, 225 and 250°C) and times (5 and 10 min) were investigated. Appearance of roasted buckwheat showed that non-enzymatic browning reaction occurred mainly at the embryo due to the presence of sugars and proteins. Microstructure of roasted buckwheat showed the formation of air cells inside the endosperm indicating the expansion of grain during roasting. Rapid Visco Analyzer profiles revealed that the extent of starch gelatinization was depending preferentially upon the roasting time rather than temperature. Total polyphenol and flavonoid content in roasted buckwheat were not significantly different from those of unroasted grains, although polyphenols and flavonoids in ethanol extracts increased slightly after roasting. Antioxidant activities of buckwheat increased after roasting.

Physicochemical properties of cherry tomato dried using the conventional hot air (HA) and superheated steam (SHS) combined with either HA or far-infrared (FIR) were measured to evaluate the effects of combined drying process on the product quality. Conventional HA drying caused the greater extent of water removal than that of SHS combined with HA or FIR due to comparatively its longer drying time, resulting the lower water activity. Total acidity of cherry tomato produced by combined drying processes was slightly lower than that of conventional HA drying. Application of SHS combined with FIR resulted in higher retention of vitamin C and lycopene content with faster rehydration capacity than those of both conventional HA and SHS with HA drying. These results suggested that SHS combined with FIR would replace the conventional HA drying process successfully in production of dried cherry tomato with appropriate quality characteristics

The aim of this study is to investigate the effects of combined drying conditions on the quality characteristics of lotus root chips. A combined drying was conducted using the superheated steam (SHS) at 220°C for 6 min, then subsequent contact drying at 150°C for specified times (2, 4 or 6 min) and finally hot air at specified temperatures (50, 60 or 70°C) for 1 hr. Changes in appearance of lotus root chips such as surface color, shrinkage and deformed shape were resulted from the extent of time and temperature of post-drying conditions. Moisture content of lotus root chips decreased with increasing the time and temperature of post-drying process. Surface color of lotus root chips was determined mainly by the contact drying step of a combined drying process. Polyphenol content was influenced by the temperature of hot air rather than the duration of contact drying. Meanwhile hardness of lotus root chips decreased significantly with increasing the duration of contact drying. These results suggested that a combined drying process with appropriate processing conditions could be applicable successfully for the manufacturing of un-fried lotus root chips.

This study was intended to investigate microwave drying characteristics of sweet potato. Two different shaped sweet potato samples (slice and shred with 6 and 9 mm in thickness, respectively) were dried under different microwave power ranging from 90 W to 900 W. Moisture ratio, drying rate, effective moisture diffusivity, dielectric properties and change in color during drying of the samples were determined. The domestic microwave oven was modified for drying of the samples. For ventilating water vapor during microwave drying, the small centrifugal fan was installed on the left upper side of microwave oven. Six well-known drying models were applied to figure out the best model for describing microwave drying curve of sweet potato. A non-linear regression analysis was used to calculate model constants. The applied models were compared based on the coefficient of correlation and root mean square error. Dielectric properties of fresh and dried samples at different drying time were measured using performance probe connected to vector network analyzer. The results showed that drying time of both samples was significantly decreased with an increase in microwave power, however, as compared with the sample shape, drying time of shredded samples was shorter than slice sample. The dried sample by 900 W was scorching and indicated the worst quality in terms of color. The Page model was most suitable for describing experimental drying data. The effective moisture diffusivity changes obtained from Fick’s diffusion method was between 0.057 ×10-8 and 2.353 × 10-8 The moisture diffusivity was increased with an increase in microwave power. The measured dielectric properties of sample at different drying time varied depending upon moisture contents of dried samples.

In this study, we investigated the change of physical properties associated with the temperature of vegetable mixed oil and fat in order to produce vegetable oil and fat suitable for plant meat production. The canola oil and coconut oil were mixed at various weight ratios, and the phase change temperatures by the ratio of two oils were measured using the differential scanning calorimetry (DSC). Storage modulus (G'), loss modulus (G") and viscosity were measured using a rheometer at 20-40°C and 0.4 Hz-100 Hz. Storage modulus (G') at constant frequency (10 Hz) was measured in a continuous section of 10-50°C. As the coconut oil content increased, the peak of the melting point moved to the lower side. The viscosity was higher in order of canola oil, mixed oil, and coconut oil, and the viscosity showed a tendency to decrease as the temperature increased. In the liquid state, it showed a tendency to increase after the value of storage modulus (G') and loss modulus (G") decreased from 0.634 Hz-1 Hz. The conversion time point of storage modulus (G') of continuous temperature change is consistent with the melting point temperature of DSC, as the passed start at 10°C, storage modulus (G') increased with an exception of canola oil. Using these results, we will pursue to produce a mixed plant oil applicable to the production of vegetable meat.

Salt is generally used for food seasonings and preservations as a common ingredient. However, excess salt intake has generated health issues such as high blood pressure, osteoporosis, stroke, and heart diseases. Recently, desires and interests of low-salt cooking have been increased among people who want healthy diets. The aim of study was to compare the physicochemical characteristics of a fermented squid sauce added with vitamin C and commercial low-salt soy sauces. Thawed and crushed squids were fermented until the solid squid became liquid at 25°C with an addition of 5% (g/g) vitamin C. Then, fermented squid sauce was heated at 100°C for 30 min and filtered. All samples were measured in multiple aspects of amino acid nitrogen, salt, sugar and water content, pH, chromaticity and brown color, and sensory test. In the results, color values showed no significantly difference between all the samples (p>0.05). Water content value of the fermented squid sauce was the highest among samples. Brown color, salt contents and sugar contents of the fermented squid sauce were significantly different than other low salt soy sauces with an exception of the sauce made with functional salt. These results showed a similar tendency as those of sensory evaluation. As conclusion, the possibility of fermented squid sauce added with vitamin C showed a possibility as a candidate of low-salt soy sauce.

Korea is the second largest coffee consuming country in Asia after the Philippines. For modern people, coffee has jumped over a favorite food and grown into a single culture. There are many processing ways to make coffee. In this study, we utilized magnetic resonance imaging(MRI) based on the principles of nuclear magnetic resonance(NMR) and achieved to acquire images with an non-destructive and non-invasive way. The samples we used in the experiment were ‘Robusta’ coffee bean(Congo). Magnetic resonance(MR) image sets were acquired using a MRI system, installed at Institution for Agricultural Machinery & ICT Convergence at Chonbuk National University. From the raw phase(Green Bean stage) to the roasted phase, we obtained MR images from each phase to monitor the internal changes. We divided experiment into 5 stages, starting with ‘Green Bean’ phase to ‘Roasted’ phase. We obtained images every 6 hours during the ‘Fermentation’ phase and every 3 hours during the ‘Dry’ phase. In MRI, we used a gradient echo pulse sequence to scan fast and to take images right after each experiment stage ends. The direction of imaging plane was coronal 30 images with 64 mm x 64 mm field of view(FOV). As MRI uses the magnetic properties of nuclei which especially hydrogen nuclei from water molecules, images could see clearly with sufficient moisture, but in ‘Dry’ phase, images obtained with noise involved. These result suggested that MRI technique was an efficient method to monitor the moisture distribution changes inside the coffee beans.

1994년 무르지 않는 토마토가 처음으로 유전자변형 식품으로 상업화를 승인 받은 이래, 미승인 유전자변형 작물의 유출은 끊임없이 보고 되고 있다. 2000년 Starlink 옥수수 유출 사건 이후에 가장 최근에는 2016년에는 미국에서 수입되는 밀에 미승인 유전자변형 밀이 혼입된 것으로 밝혀 지며 유전자변형 식품에 대한 철저한 규제와 관리가 요구되고 있다. 이에 국외에서는 자국 실정에 맞는 승인 및 미승인 유전자변형 식품의 검사 체계를 확립하여 효율적인 관리를 위해 노력하고 있다. 본 연구에서는 우리나라 실정에 맞는 검사 체계 확립을 위해 유럽 연합, 일본의 승인 및 미승인 유전자변형 식품 검사 체계를 비교ㆍ분석하였다. 일본과 유럽 연합 모두 스크리닝-이벤트 특이적 검사의 순서로 진행되나, 일본의 경우 유럽 연합과 다르게 미승인 유전자변형 이벤트의 검사 체계와 결과 분석에 대한 결정 트리를 이벤트별로 제시하는 특징을 가지고 있었다. 본 연구에서는 기존의 검사 체계를 이용하여, 우리나라에서 사용 가능한 유전자 변형 식품의 검사 체계를 제안하였다.

콩가루는 탈지한 대두박이나 탈지하지 않는 콩을 미세하게 분쇄하여 분말화 한 것으로 미국에서 입자의크기가 100mesh 체를 통과한 것으로 규정하고 있다. mesh는 강철망의 망눈의 개수를 표시하는 단위로써 가로 세로 1인치(25.4mm)사이에 있는 망눈사이의 공간의 수이고 즉 300mesh라 하면 표준체 가로 세로의길이 2.54cm 안에 구멍이 300개가 들어있는 체를 통과하는 분말의 크기를 나타낸다. 콩가루는 글루텐(gluten)이 함유되어 있지 않고 단백질함량이 많다는 면에서 밀가루와 구분되며 섬유소가 함유되어 있다는 면에서 탈지 분유와도 다르다 콩가루는 콩의 불순물을 제거한뒤 6-8 조각으로 조분쇄하여 콩껍질을 제거한 다음, 가열처리하고 이를 냉각시킨 후 분쇄하여 제조한다. 제조 과정 중의 열처리는 콩비린내를 제거하고 효소를 불활성화시켜 콩가루 냄새를 크게 향상시킬 뿐만 아니라 트립신저해제(trypsin inbibiter)를 불활성화시켜 소화율을 향상시킨다. 가열 처리에 따라 콩가루의 착색과 단백질 용해도가 감소되므로 가열방법과 가열온도, 가열시간을 적절히 조정해야 한다. 콩가루는 그 제조공정에 따라 탈지 콩가루, 전지 콩가루, 압출콩가루로 나눌 수 있는데, 전지콩가루는 콩껍질을 제거한 콩을 마쇄한 것이므로 일반성분이 콩의 자엽 부분과 비슷하고, 탈지 콩가루는 지방성분을 제거한 것이므로 지방함량이 낮고 단백질 함량이 50.0∼69.9%로 높다 압출 콩가루는 가열압출기(extruder-cooker)를 이용하여 콩을가열, 압출하여 제조한 콩가루로 지방을 제거하지 않은 콩을 그대로 사용하므로 영양가가 높고 향미가 높은 것이 특징이다. 두부는 대두의 수용성 단백질을 추출 응고시킨 gel상의 식품으로 소화율이 높고, 대두단백질은 lysine 등 필수 아미노산 함양이 높아 곡류위주의 식생활에서 부족되기 쉬운영양소를 공급하면서도 가격이 저렴한 식품이다. 본 연구는 전두부를 만들기전 첫 공정단계로 콩을 선별후 분쇄한 콩가루 50mesh, 150mesh, 300mesh, 600mesh의 국내산과 수입산으로 나눠 입자를 분석하고, 두부로 가공했을시 두부의 입자비교, 응고시간, 두부발효음료의 결과를 알아보려고 한다. 본연구에서 사용되는 전두부용 콩가루의 굵기는 300∼600mesh의 콩가루를 사용했으며, 보통 밀가루,미숫가루의 굵기는 150∼200 mesh이다. 전두부는 굵기가 가늘수록 두부의 형태는 부드럽고 단백하며, 가장 이상적인 두부의 형태가 만들어지고 다른 물질과 이루어 졌을 때 이상적인 화합물 반응으로 비추어 볼 때 맛의 형태를 좌우한다.

In plants, starch is the main carbohydrate reserve and an important ingredient in human nutrition. Nutritionally, starch is classified into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) based on the rate and degree of digestion. RS escapes enzymatic digestion in the small intestine, but in the large intestine microbial flora may ferment some RS. Malic acid is C4 carboxylic acid with two carboxyl groups. It is well known to take from 69% up to 92% of all organic acids in grape berries and leaves and is naturally produced by many organisms without showing any nutritional harm. However, properties of malic acid treated starch has not been clearly reported. The objectives of this study were to investigate the influence of pH value on low-digestible malate starch formation and digestibility in relation to structural properties of corn starch. Different pH values (1.5-8.5) of 2 M malic acid solution were reacted with corn starch in a forced-air oven at temperature of 130°C for 12 hr. Using FT-IR, carbonyl groups were detected in malate starch, indicating the formation of cross-linking by esterification. Increasing pH value of malic acid-treated sample from 1.5 to 8.5 showed an increase in degree of substitution (DS) and resulted in increase in the RS content from 18.2 to 74.8%, which was maintained after gelatinization. The granular structure of malate starches was not destroyed, and the starches maintained birefringence. This malate starch could be utilized in heat processed foods such as bread and cookies as well as in the products with reduced calories.

Native soy protein is known to possess poor interfacial activity compared to flexible proteins. Acidification could alter its structure in a way that improves its interfacial activity. This study aimed to investigate the effects of seven acids, including hydrochloric, acetic, ascorbic, lactic, malic, citric, and tartaric acid on the oil-water interfacial properties and oil-in-water emulsifying properties of soy protein isolate (SPI) at pH 3.0. The aqueous solutions of 1.5 %(w/v) SPI were adjusted to pH 3.0 with different acids, and the solution without acidification (pH 8.0) was used as a control. The zeta potential of acidified SPI solutions and SPI emulsions were positive value while it was negative value for control. The particle sizes of acidified SPI solutions were between 19-83 m (107 m for the control). The particle size of acidified SPI emulsions were 0.4 m for control, acetic, ascorbic, lactic, and malic, 1.2 m for citric and tartaric, while 20.7 m for HCl. The interfacial pressure between soybean oil and the acidified SPI solutions were between 12.7-15.4 mN/m, while SPI-control was significantly higher than that at 19.4 mN/m. The acidified SPI solution had the meaningful values of interfacial shear rheological parameters and showed viscoelastic layer, but the control was almost no viscoelastic layer. All acidified SPI emulsion showed much higher emulsifying activity index (130-158 m2/g) than the control (111 m2/g). The appearance of emulsion looked no difference over the time when observed by eyes. The evaluation of emulsion stability by the changing of particle size distribution within 40 days showed that the control and HCl was no change, while the others tended to increase particle size.

김치 제조공정 중 절임배추 제조공정은 원료검사, 세절, 절임, 세척, 탈수, 포장의 공정으로 구성되며 절임배추의 품질은 제조공장의 생산설비, 절임환경 및 절임조건에 따라 달리 나타난다. 생산시스템은 제조공정을 효율적으로 수행하기 위한 사람과 설비 및 일하는 방법인 업무 프로세스의 집합을 말하며 제조현장과 관련된 여러 가지 자동화 시스템 중 MES(Manufacturindg Execution System)는 주문에서 최종 제품에 이르기까지 생산 활동에 필요한 최적의 정보를 관리하는데 필요한 시스템이다. 본 연구에서는 절임배추 제조공정을 보다 효율적으로 관리 할 수 있는 절임배추 제조관리시스템(MES)을 개발하고 이를 통해, 김치 제품의 생산관리를 원활하게 할 수 있도록 하였다. MES 데이터베이스 시스템 설계 및 구현을 위한 ERD(Entity Relationship Diagram)는 제조 공정별로 품질기준을 설정하여 표준화하여 적용하였으며 절임배추의 생산관리는 바코드 형식의 NFC(Near Field Communication) Tag를 이용하였다. 원자재관리를 위한 모니터링 시스템은 스마트 폰을 연동한 APP(Application)형태로 Eclipse 4.4.1 luna를 통해 개발하였으며, 모든 데이터의 통신은 MES내의 Open API(Application Programming Interface)를 통해 주고 받도록 설계하였다. 결과적으로 절임배추 생산을 위한 원재료 입출고 이력 및 생산이력은 MES 시스템을 이용하여 관리가 가능하며, 추후 양념 등을 포함한 김치 제품을 관리할 수 있는 기능을 포함하는 전주기 김치 제조관리시스템의 구축이 필요하다.

두유는 단백질, 지질, 다당류 등이 에멀션과 서스펜션 형태로 혼합된 분산 시스템이다. 두유의 안정성은 제조조건과 균질화 방법에 따른 입자의 크기와 열처리 조건 등에 의하여 크게 영향을 받으며, 일반적으로 점증제와 계면활성제를 사용하여 향상시킬 수 있는 것으로 알려져 있다. 본 연구에서는 양친매성의 진세노사이드를 함유한 인삼 분말의 첨가와 열처리가 고압 균질화하여 제조한 비지 분리 두유의 안정화에 미치는 영향을 분석하였다. 전두유의 비지를 분리한 후 2% (w/w)의 인삼 분말을 첨가하였으며, 이때 진세노사이드 함량(Rg1, Rb1, 및 Rg3의 합량)은 0.088 mg/100g soy milk 이었다. 이후 두유를 열처리(90°C, 10 min)하거나 열처리 하지 않고 고압 균질화(4500 psi)하여 인삼 분말을 함유한 비지 분리 두유를 제조하였다. 제조한 두유 샘플들의 고형분 함량은 6.7-7.5% (w/w), pH는 6.4-6.8, 제타 포텐셜은 -7-0.3 mV, 입도 크기는 17-23 μm 범위에서 측정되었다. 두유의 저장 안정성은 두유를 45 ml 유리관에 넣고 25°C에서 144 h 동안 저장하면서 분리된 상층부와 하층부의 입도크기, 투과도, 상분리 현상 등을 측정하여 분석하였다. 인삼 분말을 첨가하지 않은 비열처리 두유의 경우, 저장 중 상층부의 입도 크기는 21.6±0.2 μm에서 6.6±0.4 μm로 감소하였고 투과도는 5.2±0.0%에서 77.3±0.1%로 급격히 증가하였다. 2%의 인삼 분말을 첨가한 비열처리 두유의 경우, 저장 중 상층부의 입도 크기는 21.6±0.1 μm에서 38.5±3.1 μm와 투과도는 0.8±0.0%에서 58.1±0.1%로 각각 증가하였다. 인삼 분말을 첨가하지 않은 열처리 두유의 경우, 저장 중 상층부의 입도크기는 17.4±2.4 μm에서 1.1±0.0 μm로 감소하였고 투과도는 7.3±0.1에서 14.0±0.1로 증가하였다. 2% 인삼 분말을 첨가한 열처리 두유의 경우, 상층부의 입도 크기는 22.9±0.4-24.9±0.5 μm, 투과도는 1.0±0.0-4.3±0.1% 범위에서 일정한 값을 유지하여 가장 높은 저장 안정성을 나타내었다. 저장 중 하층부에서는 인삼 분말첨가와 열처리에 따른 입도크기와 투과도는 각각 12.5±0.9-24.5 μm와 0.3±0.0-7.3±0.1% 범위로써 유의적인 차이는 보이지 않았다.

This study investigated the interactions between starch and starch - derived materials and fluorescent materials. Many researchers have used fluorescent materials to monitor the internal structure of starch, which is an effective method. The purpose of this study was to observe the internal structure of starch by using fluorescent material and to check how much fluorescent material could be loaded inside the starch. For this, a standard curve of the fluorescent material was obtained and a linear graph corresponding to the concentration was obtained. Next, the incorporation of the fluorescent material into the starch was confirmed by CLSM in the infusion experiment. Infusion experiments were carried out to quantify the amount of fluorescent substance in starch, but the error was confirmed in this experiment. The error was caused by the action of starch and the fluorescent substances FD4 and NaFl, resulting in an increase or decrease in fluorescence intensity. To find the cause, dextrin, amylose and amylopectin, which are starch-derived substances, and α, β, γ-cyclodextrin, which can form inclusion compounds, were used. The fluorescent materials were merbromin, NaFl, and FITC. As a result, the fluorescence intensity of the fluorescent material was significantly influenced by the concentration of amylose and amylopectin. This result implies that there may be errors in the analysis of the phenomenon or observation of the starch using the fluorescent substance. We still do not know exactly the cause of this phenomenon, so further research is needed.

활성칼슘 수용액(0.2%, w/w, CaO/distilled water, CaO) 처리와 유전체 방벽 대기압 콜드 플라즈마(dielectric barrier discharge atmospheric cold plasma, DACP) 처리를 병합하여 감귤에 접종된 Penicillium digitatum에 대한 저해 효과와 저장 기간에 따른 이화학적 특성을 연구하였다. 처리 변수는 3분 동안 CaO에 침지 처리하거나, 처리 전압 35.2 kV에서 2분동안 DACP 처리하거나, CaO와 DACP 처리를 병합하는 것이었다(CaO-DACP). P. digitatum 저해 효과는 곰팡이 발생률(disease incidence, D.I., %)로 확인하였다. 이화학적 특성 분석을 위해 감귤은 4 °C에서 35일, 그리고 25 °C에서 14일간 저장되었다. CaO-DACP 처리된 감귤에서 D.I.가 유의적으로 낮게 나타났다(p<0.05). DACP 처리 직후 감귤의 호흡률, 색도, 당도, pH, 그리고 적정 산도는 무처리 시료와 유의적으로 차이가 없었다(p>0.05). 4 °C 저장 14일차와 25 °C 저장 3일차까지 CaO-DACP 처리된 감귤은 단독 DACP 처리된 시료보다 유의적으로 낮은 호흡률을 보였다(p<0.05). 모든 저장 온도에서 단독 DACP와 CaO-DACP 처리된 감귤의 명도는 저장 기간 동안 무처리 시료와 동일한 경향으로 감소하였다(p<0.05). DACP 처리는 저장 중 감귤 과육의 당도, pH, 그리고 적정 산도에 유의적으로 영향을 미치지 않았다(p>0.05). Scanning electron miscopy (SEM) 결과, DACP 처리와 CaO-DACP 처리된 감귤은 무처리 시료의 표면보다 매끄러운 경향을 보였다. 본 연구를 통해 DACP 처리와 CaO-DACP 처리가 감귤 저장 중 품질 변화를 최소화시키는 살균 기술로 사용될 가능성을 확인할 수 있었다.

The purpose of this study was to utilize the stem of Opuntia ficus-indica and to optimize the extraction conditions and standardize extract process for water soluble dietary fiber and solid. Extraction process was optimized by applying various conditions such as pH, ethanol concentration, extracting temperature and time. Maximum extraction yield for water soluble dietary fiber and solid were obtained using 100% water, indicating that ethanol hampered extraction. Also, extraction was unstable with higher heat, longer extraction time, and low acidic conditions. Maximum extraction of water soluble dietary fiber (27.92%) and solid (5.6 g) were obtained at 50°C, pH7, and 7 hr extraction time. Extract had antioxidant capacity at 1105.98 mg vitamin C equivalents (VCE) on ABTS assay and 118.10 mg VCE on DPPH assay.

Oats (Avena satica L.) are an important source of dietary fiber mainly composed of β-glucans, which is reported to be effective in lowering of cholesterol and decreasing the risk of heart attack. Subcritical water extraction (SWE) is a new and promising method for the extraction of β-glucan due to its polarity-selectivity, efficiency of recovery, time-efficiency, and lower cost. In this study, efficiencies of the SWE were investigated for the extraction of β-glucan from oat flour. The conditions for maximizing the extraction efficiency were determined by varying temperature (110-190°C), pH of solvent (pH 3.0-10.6), static time (5-20 min) and particle size of oat flour. The amount of β-glucan was determined with a ‘Mixed-linkage β-glucan’ assay kit (Megazyme International Ltd.), according to McCleary and Codd (1991). The overall results showed that the concentration of β-glucan was highest under the following conditions: extraction temperature of 200°C, pH value of 4.0, static time of 10 min, and particle size of 425-850 μm. The extraction yield under the optimum condition was 6.98±1.17 g/100 g oat flour, which was over two-fold higher than that obtained using hot water extraction method (60°C, 3 h). Therefore, SWE is a feasible alternative for extracting soluble dietary fiber (β-glucan) from oat flour.

Citrus fruit is important source of flavonoids, mainly flavanones which are narirutin and hesperidin. Those citrus flavonoids have been found to have health-related properties including antioxidant, anticancer, and anti-inflammatory. The main purpose of this study was to verify that the extraction of narirutin and hesperidin from Citrus peel can be more effective by combining pulsed electric field (PEF) pre-treatment and subcritical water extraction (SWE). Citrus unshiu peels were treated with PEF under conditions of electric field strength (3 kV/cm) and times (1 and 2 min). Subsequent SWE was conducted by using a Dionex Accelerated Solvent Extractor (ASE, Model 350) at extraction temperature 170°C for 10 min. The total flavonoids content was measured by using the aluminum chloride colorimetric method and the antioxidant capacity was analyzed by the Ferric reducing antioxidant power (FRAP) assay using spectrophotometer. The concentrations of narirutin and hesperidin were increased as PEF pre-treatment time increased. The highest concentrations of narirutin and hesperidin were 13.41 mg narirutin/g dry citrus peel and 141.16 mg hesperidin/g dry citrus peel at PEF pre-treatment condition of 3 kV/cm and 2 min. The total flavonoids contents of the extracts increased 105.2% and 123.1% for citrus peel PEF treated at 1 and 2 min, respectively. In addition, compared to the untreated sample, PEF pre-treatments of 1 and 2 min increased the antioxidant capacity of the extracts 109.2% and 160.8%, respectively. Therefore, the results demonstrate the potential of PEF pre-treatment to improve the SWE of flavonoids from citrus unshiu peel.

The prevalence of chronic diseases has increased steadily over the last 20 years. The side effects of drugs used to treat chronic disease have always been a problem, owing to the need for long-term medication. Many studies have attempted to discover drugs from natural sources with fewer side effects. In this study, we investigated the possibility of using jujube leaf as a potential anti-diabetic drug source or food supplement. The IC50 values of acarbose and jujube leaf extract on a-glucosidase were 2.59 and 0.37 mg/mL, respectively. In vitro tests showed that the inhibition of a-glucosidase was maintained after the jujube extract was passed through a simulated digestive system, but no inhibition of a-amylase was observed either before or after the in vitro digestion. The jujube leaf extract showed mixed non-competitive inhibition. Jujube leaf extract is expected to be safer and cheaper than synthetic inhibitors.

Subcritical water extraction (SWE) is an eco-friendly new extraction technology because it does not contain harmful organic solvent and has high extraction efficiency in a short time compared with conventional extraction methods. Blueberries (Vaccinium corymbosum) are widely known as superfood due to rich source of anthocyanin (malvidin-3-o-galgctoside) and antioxidant activity. In this study, optimal extraction condition of SWE from blueberries was determined and compared with the conventional extraction methods. SWE was carried out using a Dionex Accelerated Solvent Extractor (ASE, Model 350) under conditions of temperatures (110, 130, 150 and 170°C) and times (1, 3, 5 and 10 min). Total anthocyanin of SWE extracts was compared with hot water (60°C, 1 h) extract and pressed juice extract. The total anthocyanin content was determined by pH differential method. Considering both the extraction time and temperature conditions, the highest content of total anthocyanin content was 0.455 mg/g FW Vaccinium corymbosum at 130°C for 3 min. At high temperature and long extraction time, the anthocyanin in the blueberries will undergo thermal degradation due to low stability of anthocyanin at extreme condition. Besides, maximum yield of anthocyanin from blueberries using SWE was about 1.2 and 3.8 times more higher than hot water extract and pressed juice extract, respectively. Therefore, SWE is faster and more efficient method to extract anthocyanin from blueberries than conventional extraction methods. This study shows a possibility of SWE applied to food processing industry.