La France pear is one of the most popular European pears in Japan. Its typical charms include the fine aroma and the smooth texture. In Japan, Yamagata prefecture is one of the major La France pear-producing areas. To promote new local specialty processed foods and drinks in the Yamagata district, we developed two new food materials made from La France pear. One is a powdered material, “La France powder”, and the other is a liquid material, “La France essence”. Their beneficial characteristics include their natural and fine aroma. They are currently being utilized in the development of many new processed foods, drinks, etc. In this context, an overview of their development and examples of their applications are presented.

View full abstract

The effects of heating temperature and time on browning, DPPH-radical scavenging activity and polyphenol-like activity of molasses from sugarcane were investigated. The browning, DPPH-radical scavenging activity and polyphenol-like activity of molasses heated to between 120°C and 160°C were increased in comparison with unheated molasses. The browning of molasses heated to 120°C and 140°C increased with heating time, and was nearly 9.5 times greater than unheated molasses after heating for 60 minutes. The browning of molasses heated to 160°C exponentially increased after heating for 10 minutes, and was nearly 16.7 times greater than unheated molasses after heating for 20 minutes. The DPPH-radical scavenging activity of molasses heated to 120°C for 50 minutes, 140°C for 10 minutes, and 160°C for 10 minutes was four times greater than that of unheated molasses. The alterations in DPPH-radical scavenging activity were similar to the polyphenol-like activity pattern with heat-processing. The heated molasses with the highest polyphenol-like activity, processed at 160°C for 20 minutes, showed stronger antimutagenicity than unheated molasses. These results indicate that the heat-processing of sugarcane molasses is a viable method for the enhancement of food functions in sugarcane molasses.

View full abstract

Lactobacillus fructivorans has been identified as a spoilage bacterium in dressing, since it is strongly resistant to acetic acid. In recent years, the spoilage of dressing has increased in frequency because of the reduced concentrations of both acetic acid and NaCl in dressings. To develop new control methods for L. fructivorans in low-acetic acid dressing, the properties of L. fructivorans were investigated. Doubling time of the bacterium was longer than that of other lactic acid bacteria. In addition, the incorporation rate of fluorescent dye or esterase activity of the bacterium was also lower than observed with Lactobacillus brevis. These results suggest the importance of increasing the incorporation of acetic acid into the bacterial cells. For this purpose, chitosan was employed. Cells treated with chitosan showed a nearly 10-fold increase in the incorporation of SYTO green compared to control cells. Chitosan adsorbed onto the surface of L. fructivorans and increased the surface hydrophobicity of the cells. The chitosan-treated cells localized at the water-oil interface of the dressing, resulting in decreased combined antibacterial action of chitosan and acetic acid. The addition of 0.04 % thiamine dilaurylsulfate, an amphipathic antibacterial compound, completely inhibited the growth of L. fructivorans in the dressing with 0.04 % chitosan and 3.5 % NaCl at pH 4.1, for 60 days at 30°C.

View full abstract

We evaluated a variety of radical scavenging abilities of hot extracts of mushrooms, by employing the electron spin resonance (ESR) spin trapping method and oxygen radical absorbance capacity (ORAC) assay. The ESR spin trapping method using 5-(2,2-dimethyl-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline-N-oxide (CYPMPO), as the spin trapping reagent, identified the hydroxyl radical (•OH), superoxide radical (O₂^-), alkoxyl radical (RO•) and singlet oxygen (¹O₂). The ESR adduct signals were sensitive and stable. The trapping activity indicated L-ascorbic acid (from •OH), α-lipoic acid (from O₂^-), glutathione (from RO•) and ¹O₂ equivalents. The radical scavenging abilities of hot water extracts from 13 mushroom species did not correlate with the corresponding ORAC values. However, our results indicate that an important feature of methods for evaluating antioxidant activities should be the determination of the radical scavenging abilities by ESR spin trapping.

View full abstract

Vegetables are important sources of vitamins and minerals ; however, they also contain nitrate anion (NO₃^-), which is a risk factor for vascular diseases and cancer. This study was conducted to investigate the distribution of NO₃^- and vitamin C (VC) in Japanese radish, which is harvested throughout the year, and the changes in their contents resulting from different fertilization methods. The anatomical distribution of NO₃^- and VC differed significantly throughout the Japanese radish. Namely, NO₃^- in the tip of Japanese radish root was higher than in the end, in all regions of the cortical bundle, the vascular bundle, and the center. On the other hand, the VC content in the end of the root was higher than in the tip in all regions. The content of NO₃^- in the roots was positively correlated to the amount of nitrogen fertilizer applied during field growth. Treatments with low amounts of basal nitrogen fertilizer resulted in decreased NO₃^- in the roots. These results suggest that open cultivation with low amounts of basal fertilizer produces good quality Japanese radish containing high levels of VC and low levels of NO₃^-.

View full abstract

Generally, apple thinning is employed to enable the growth of larger fruit. The thinned out unripe apples contain high amounts of polyphenols. Anti-obesity effect of dietary polyphenols from unripe apple (UP) was examined in rats in this study as a potential utilization of unripe apples. UP (0.17 %) was given to Sprague-Dawley (SD) rats under a pair-feeding condition for 62 days. Dietary UP suppressed the increase in white adipose tissue mass, and plasma and liver triglyceride (TG) levels. Increases of plasma insulin and their levels were also significantly inhibited by dietary UP. Gene expression of hepatic fatty acid β-oxidation enzymes increased in rats fed UP. Moreover, dietary UP increased the gene expression of hepatic peroxisome proliferator-activated receptor α. In addition to these actions, UP inhibited digestive enzyme activities of carbohydrate and fat, and micellar solubility of TG, cholesterol and bile acid in vitro. The inhibition of absorption of glucose and hydrolyzed fat by UP was observed using the everted sac method. Thus, UP may exert an anti-obesity effect through modulation of fatty acid metabolism in liver and inhibition of absorption of carbohydrate and fat. Therefore, unripe apple containing high levels of polyphenols may be useful as a prophylactic for obesity.

View full abstract

The present study was conducted in order to determine the interactive effects of L-ascorbic acid 2-glucoside (AA-2G) and trehalose on their anti-oxidant actions. Linoleic acid was readily peroxidized in the presence of Fe³⁺ and L-ascorbic acid (AsA). In contrast, the combination of AA-2G and Fe³⁺ had no effect on chemical peroxidation. On the other hand, the peroxidation of linoleic acid induced by the coexistence of Fe³⁺ and AsA was inhibited by trehalose in a dose-dependent manner. Further analysis of the action of trehalose as a novel anti-oxidant by the oxygen radical absorbance capacity (ORAC) method revealed that trehalose synergistically stimulated the ORAC values of AA-2G, but had no synergistic effect on those of AsA. These findings indicate that a mixture of AA-2G and trehalose is advantageous as an anti-oxidant food additive.

View full abstract