乳酸菌は主にグルコースなどの単糖類を資化して乳酸発酵を行うが，ニンニクの主成分である多糖類のフルクタンは一般的に発酵できない．我々はニンニク乳酸菌発酵食品を作る目的で新たにフルクタン資化性菌を探索し，ラッキョウ塩漬けからLactobacillus plantarum S506株を分離した．S506株はニンニクフルクタンのみを糖質源として効率よく乳酸発酵することができた．分離したS506株をスターターとして得られた発酵ニンニクエキスは，BALB/cマウス由来マクロファージ様細胞株のJ774.1細胞を使った試験において自然免疫強化の指標となるインターロイキン-12（IL-12）産生量を顕著に増大した．このIL-12産生促進作用の主な有効成分は発酵により新たに生成した成分であることが推察された．このような新たな免疫機能が付与されたニンニク乳酸菌発酵食品は健康維持に役立つ食品として期待される．
This study investigates the effect of the texture of agar gel as a model solid food on gastric digestion using a human Gastric Digestion Simulator (GDS). The GDS, which simulates gastric peristalsis, can investigate physical digestion phenomena such as disintegration of solid foods. Agar gels with different fracture stresses (56 to 219 kPa) and constant fracture stain (29%) were prepared by varying the agar concentration (1.5 to 4.5 wt%). Direct observation demonstrated that agar gel particles initially cut to a 5.0 mm cube gradually reduced in size and broke down into random shapes during simulated gastric peristalsis. The size distribution of the agar gel particles after the digestion experiment was analyzed using the sieving method. The fraction larger than 2.36 mm, which corresponds to the pylorus size, decreased with time: the wet weight ratio of that fraction to the total amount of agar gel particles was 18.0% at 180 min in the case of 1.5 wt% agar gel. The agar gel concentration did not affect the size distribution after 180 min, which shows that fracture strain plays a more important role in agar gel digestion. Our results provide useful information about the relationship between solid food texture and gastric digestion.
Adsorption isotherms of hydrophobic substances (methylparaben, coumarin, vanillin, isovanillin, and caffeine) onto a chromatographic organic monolith were measured at 24℃. Adsorption isotherms of coumarin and caffeine were linear and were expressed by the Henry equation. On the other hand, the isotherms of methylparaben, vanillin, and isovanillin were non-linear and could be expressed by combining the Henry and Langmuir equations. Among the adsorbates having almost the same molecular masses, vanillin was adsorbed the most on the organic monolith, and methylparabene followed. The adsorbate hydrophobicity was not a main parameter reflecting the adsorbability, but any specific interaction between the adsorbate and the monolith would play an important role on the absorbability onto the monolith.