Changes in contents of free sugars, amino acids, and fatty acids of legumes were analyzed for each phase of in vitro digestion. In addition, contents of resistant starch in raw and digested pulses were compared. Soybeans, kidney beans, cowpeas, and chickpeas were analyzed. An in vitro digestion model was used to analyze contents of nutrients using LC-MS and GC-MS. Stachyose in kidneybean, cowpea, and chickpea increased as the digestion phase progressed. In four types of legumes, raffinose slightly decreased or showed no significant difference between the Oral phase and the BBMV phase. Content of glucose, a monosaccharide, increased during the BBMV phase. During the digestion phase, levels of free amino acids and free fatty acids also increased. Content of resistant starch was reduced compared to that in the raw material. It was 0.01g/100 g food in soybean, 1.06 g/100 g food in red kidney bean, 0.77g/ 100g food in cowpea, and 0.76 g/100 g food in chickpea. It was confirmed that nutrients in the in vitro digestion model were liberated at each digestion phase with changes in the content of resistant starch. These results are expected to be used as fundamental data for obtaining bioavailability of nutrients.

본 연구는 위장 단계의 소화과정에 관여하는 Gastric lipase (GL)를 반려견을 위한 정적 체외 소화모델(Static in vitro digestion model)에 적용을 검토하기 위하여 실시되었다. GL의 첨가가 체외 소화과정 동안 건물(Dry matter; DM), 조단백질(Crude protein; CP) 그리고 조지방(Ether extracts; EE) 소화율에 미치는 영향을 평가하였다. GL은 위장 소화단계에서 첨가되었다. 위장(39℃, 2 hr.)과 소장(39℃, 4 hr.) 소화 후에 비소화 분획을 분리하였다. 그리고 실험사료와 분리된 비소화 분획에서 DM, CP 그리고 EE 수준을 측정하고 각각의 소화율을 계산하였다. 위장과 소장 소화단계에서 측정된 DM, CP 그리고 EE 소화율은 Control과 GL 그룹 사이에서 통계적으로 유의한 차이는 관찰되지 않았다(p>0.05). 결과적으로 우리의 체외 소화모델에서 GL의 첨가는 DM, CP 그리고 EE의 소화율에는 영향을 미치지 않는 것으로 나타났다. 따라서 이와 같은 결과는 정적 체외 소화모델을 이용한 소화율의 평가에 있어서 GL의 역할은 다소 제한적일 수 있다는 것을 시사한다.

본 연구는 생후 12개월령의 염소를 사용하여 앞다리, 뒷 다리, 등심 및 갈비 부위로 분할하여 in vitro 소화실험을 통해 부위별 단백질 가수분해도 및 아미노산 조성을 조사 하였다. 이 때, 소고기 및 돼지고기의 분할육을 이용하여 염소고기와 비교, 분석하였다. 염소고기 분할육 중 뒷다리 (8.32%) 및 갈비(8.32%)가 가장 높게 단백질 가수분해도가 나타났으며, 염소고기의 갈비 부위는 갈비 분할육 중 가장 높은 단백질 가수분해율을 보였던 돼지고기(8.57%)와 유의 차가 없었다 (P>0.05). In vitro 소화 전에는 염소고기 분할 육 중 등심에서 글리신(11.03%)이, 앞다리에서 글루타민 (53.44%)이 다른 고기 종류 및 분할육들에 비해 유의적으 로 높은 비율로 포함된 것이 확인되었다(P<0.05). In vitro 소화 후에는 염소고기 갈비 부위에서 라이신(17.54%)이 가 장 높은 비율로 포함된 것으로 확인되었으며, 소 갈비 부 위보다 유의적으로 높았다(P<0.05). 본 연구는 염소고기 분 할육의 단백질 가수분해도 및 아미노산 조성을 제공하며 단백질 소화양상 및 생체 이용률을 평가하기 위한 기초 자 료로써 활용되어질 수 있을 것으로 사료된다.

Tartary buckwheat has established itself as a functional food source because of its basic nutrition and phenolic compound contents, such as dietary fiber (DF) and rutin (RU). However, little information has been obtained concerning the comparative effects of DF and RU on the in vitro and in vivo glucose responses of tartary buckwheat flour. Moreover, the relationship between the flour’s in vitro starch digestibility and its components’ blood glucose response is not well-known. This study found that DF and RU reduced rapidly digestible starch (RDS) by 37.32→33.88% and 41.71→30.28%, whereas they increased resistant starch (RS) by 30.47→31.46% and 28.41→36.78%, respectively. Furthermore, RU had a lower glycemic index (GI) compared to DF. The regression equation for the in vitro and in vivo data from RU exhibited positive correlation (R 2 = 0.99); however, DF did not display positive correlation, which indicates that the in vitro and in vivo GI mechanisms by DF and RU are different.

The gastro-intestinal behaviors of foods influence their physiological functions in the human body. In-vitro methods simulating digestion processes have been extensively used to study the gastro-intestinal behaviors of foods due to more rapid and less expensive advantages. However, there is a lack of systematic studies to monitor the rheological changes of the food digesta in real time. In this study, rice-based products (specifically, extruded noodles) were prepared with three varieties of rice flours with different contents of amylose and their physicochemical properties and in-vitro digestibility were then characterized from a rheological point of view. The rice flours with higher amylose contents exhibited greater stability to dual mixing and higher degrees of starch gelatinization and retrogradation in thermo-mechanical measurements. In addition, greater elastic properties were clearly observed in the high amylose rice samples. The noodles which were produced with high amylose rice flour had a harder texture and reduced cooking loss. When the rheological changes of the extruded rice noodles were monitored in real time during the in-vitro starch digestion, the rice noodle digesta with higher amylose content exhibited greater viscosities throughout the simulated oral-gastric-intestinal digestion steps. The flow behavior of the rice noodle digesta consisted of the Power-law region and infinite shear plateau that were satisfactorily characterized by the Sisko model (R2>0.99). Hence, this study was conducted to investigate the physicochemical and in-vitro digestibility of extruded rice noodles with different amylose contents. These results can provide a promising opportunity for the food industry to research in-vitro digestion and physicochemical characteristics of rice-based products.

As one of the staple crops, rice has been widely applied to value-added products, giving the food industry new avenues of use. Although the quality attributes of various rice products have been reported, there is a lack of detailed information on the rheological behaviors of rice products during digestion that are related to their bioaccessibility in the human body. In this study, three rice varieties with different amylose contents were utilized to produce flours and extruded noodles. In-vitro methods simulating starch digestion processes were then established to monitor their oral-gastric-intestinal rheological behaviors. The rice flour with high amylose content exhibited lower values of water absorption index/swelling power and higher pasting parameters that were in good agreement with the Mixolab thermo-mechanical results. The extruded rice noodles showed lower cooking loss and higher hardness with increasing levels of amylose. When the in-vitro viscosities of rice flours and noodles were measured using a rotational rheometer with the custom-made starch cell, their viscosities had a tendency to decrease as the in-vitro digestion progressed. Specifically, the rice samples with high amylose content exhibited higher viscosity than those with low amylose content under the simulated oral, gastric, and intestinal conditions. Hence, this study was conducted to investigate the physicochemical and in-vitro rheological properties of rice flours and extruded noodles with different amylose content. The results provided a promising opportunity for the food industry to study in-vitro digestion of rice-based products with the advantages of being more rapid and less expensive.