The 7S and 11S globulins are major components of soybean protein. We developed a novel freeze-thaw method for crude fractionation of these proteins in soymilk. Raw soymilk was frozen at -30°C, and then thawed at 10°C for 24 h. The freeze-thawed soymilk was separated into two layers, and the weight ratio of the upper layer (UPL) and lower layer (LWL) was 3 : 2. On SDS-PAGE analysis, the 11S/7S ratio was 0.14 in the UPL, and 1.7 in the LWL. We mixed UPL with LWL in various ratios, and prepared tofu curds from these mixtures. The breaking stress of the tofu curd increased with LWL ratio. The curd made from UPL was soft and smooth, whereas that made from LWL was firm. We developed a novel dessert-like product made from UPL and a novel sausage-like product made from LWL. These results show that rough separation of 7S and 11S globulins in raw soymilk can be achieved using a simple freeze-thaw treatment, thus facilitating the development of new food products.

View full abstract

In order to investigate the effects of changes in the endosperm protein composition due to the low glutelin gene Lgc1, the processing characteristics of boiled rice and rice flour were investigated using two sets of near-isogenic line pairs for the Lgc1 locus. On measurement of gelatinization physical properties, we found that final viscosity and consistency were significantly higher in low glutelin lines. On physical property measurement with boiled rice, surface stickiness was significantly decreased in the low glutelin lines, and a significant decrease was seen in the balance of hardness to stickiness. On water absorption of the polished rice grains at 15°C, a significant difference was not observed between the low glutelin lines and normal protein composition lines. In this study, the low glutelin lines showed higher amylose content than normal protein composition lines. Therefore, the differences between low glutelin lines and normal protein composition lines could not be determined based on protein composition alone. However, these differences are the cause of the low palatability of boiled rice and are responsible for the processing characteristics of flour made from low glutelin cultivars possessing the Lgc1 gene.

View full abstract

Zeolite, which is designated as one of the food additive, is known to absorb radioactive cesium by its cation exchange capacity. In this study, we investigated the effect of zeolite treatment on the removal of radioactive cesium in apple juice made from apples produced in FY2011. Removal of the radioactive cesium in apple juice was possible by the addition of zeolite. There was a positive correlation between the reduction of radioactive cesium and the surface area of the zeolite as well as treatment time. It was also shown that the efficacy of radioactive cesium removal was decreased by lowering the treatment temperature. Zeolite treatment did not affect the contents of sugars and malic acid in the apple juice ; however, it increased the concentrations of the cations Na⁺ and Ca²⁺, and decreased K⁺. Moreover, a slight change in apple juice flavor was observed after zeolite treatment.

View full abstract

We investigated the effects of defatted-dried chicken skin powder (DCS) containing sphingomyelin (SM) on human facial skin conditions. A placebo-controlled, double-blind 12-week study of DCS (1 g/day ; SM2 mg/day) was conducted on 36 female volunteers who tend to have dry skin. In the DCS group, the moisture of the stratum corneum of cheek tended to increase after 12 weeks. In the subjects whose moisture of cheek was less than 35 arbitrary unit, the DCS group was significantly higher than the placebo group. After 12 weeks, skin elasticity showed significantly increase in the DCS group compared with 0w. These results indicate that the ingestion of DCS improves dry facial skin.

View full abstract

We investigated the phase separation of egg white protein (EWP)/agar co-gel. We focus herein on the relationship between the continuous phase and fracture properties, as well as the formation of a bicontinuous phase. In this study, co-gels were prepared with seven different ratios of EWP and agar. The fracture properties of co-gels were analyzed by large deformation test. Gels were classified into three groups : similar properties as EWP (group 1) or agar (group 3), and novel properties (group 2). The microstructure of co-gels was observed by confocal laser scanning microscopy and scanning electron microscopy. The results suggested that all co-gels had a phase separation structure and were also classified into three groups : EWP continuous phase (A), bicontinuous phase (B) for both EWP and agar, and agar continuous phase (C). The three phase groups (A, B, C) corresponded respectively to the three groups (1, 2, 3) classified by fracture properties. The results demonstrated that the continuous phase component contributed to the physical fracture properties of co-gels, and the formation of a novel bicontinuous phase enhanced the mechanical strength of the phase-separated gels.

View full abstract

In order to study the molecular weight changes in milk allergens after heat treatment, commercial cow milk and a mixture of β-lactoglobulin and lactose, were heated on a stainless steel tray at 120°C for 60 min. SDS-PAGE analysis showed that heated milk had milk proteins with slightly higher molecular weight. In the case of β-lactoglobulin, heat treatment induced dimeric and polymeric proteins, and heating with higher concentrations of lactose induced a molecular shift in the β-lactoglobulin band to a higher molecular weight with carbohydrate modification. In addition, monomeric, dimeric and broad polymeric proteins stained on Western blot analysis with anti β-lactoglobulin antibody suggested that heat treated β-lactoglobulin retained it's immunogenicity.

View full abstract

Proteoglycan (PG)-containing powder was prepared from salmon nasal cartilage and extracted with the following solutions : distilled water ; 4 M guanidine hydrochloride ; 7 M urea ; 0.5 M sodium hydroxide ; 4 % acetic acid ; 1 % malic acid ; 1 % citric acid ; and 1 % ascorbic acid. Comparisons of PG between the solvent types revealed varying amounts of uronic acid and protein. DEAE Sephacel ion exchange chromatography showed that the PG elution patterns of all extracts were similar to those of PG prepared by the conventional 4 % acetic acid extraction method, thus demonstrating their similar electrostatic properties. Sepharose CL-4B gel filtration chromatography was then used to investigate molecular weight distribution, and the rate of PG distribution in the high molecular weight fraction was shown to be higher in the water extracts than in both the acid and alkaline extracts. These results suggest that hig-molecular-weight PG is the natural form of PG.

View full abstract

Visualization is defined as any technique for creating images, diagrams or animations to communicate a message. Visualization through visual imagery has been an effective means of communicating both abstract and concrete ideas since the dawn of man. There is great interest in quantifying the various aspects of structure, and in many cases, this involves imaging the structure and performing measurements on the images by image processing and analysis. The images may be simple macroscopic or microscopic light images, including confocal laser scanning microscopy (CLSM), but may also include images from either transmission or scanning electron microscopes (TEM and SEM), atomic force microscope (AFM) images of surfaces, magnetic resonance imaging (MRI) or computed tomography (CT) images of internal structure. The topics covered are the acquisition and processing of the images, the measurement of appropriate microstructural parameters, and the interpretation of these numbers, particularly with regard to the issues that the structures are generally three-dimensional while the images are usually two-dimensional.
I hope that this article is able to usefully summarize the basic procedures, and that it will be of use to researchers in food science fields.

View full abstract