In order to clarify functional differences between non-degassed or degassed coffee bean extracts, we examined the hypouricemic effect of each coffee bean extract in mice. In previous reports, we showed that degassing decreased a large quantity of volatile compounds in coffee extracts and influenced the immunostimulatory action and anxiolytic effect of coffee. In this study, serum uric acid levels were significantly reduced (p<0.05) following administration of the non-degassed roasted coffee bean extract in mice. Moreover, we found that 2 kinds of sulfur compounds and 1 kind of pyrazine compound, which were decreased by degassing, significantly reduced (p<0.05) serum uric acid levels in oxonate-induced mice. To elucidate the mechanism of the hypouricemic effect of non-degassed roasted coffee bean extract, we examined xanthine oxidase activity. Results showed that the non-degassed coffee bean extract had an inhibitory effect on xanthine oxidase; moreover, the longer the degassing time, the weaker the effect.

We examined the effects of dietary bitter melon juice (BMJ) freeze-dried powder (BMJ-F) on lipid metabolism in rats fed diets with low fat (Experiment 1) as well as of spray-dried powder of a mixture of BMJ and dextrin (1:1, w/w, BMJ-S) on lipid metabolism in rats fed diets with different levels of dietary fats (Experiment 2) and in those fed diets with or without dietary cholesterol (Experiment 3). In Experiment 1, we found that feeding BMJ-F markedly decreased triglyceride (TG) levels in the serum and liver of rats, while the residual fiber fraction lowered cholesterol levels in the serum of these animals. Next, the BMJ and residual fiber fractions thus obtained were freeze dried, powdered (Experiment 2), and evaluated. We confirmed in Experiment 2 that feeding BMJ-S markedly decreased hepatic TG levels, although the reduction was greater in animals fed high fat-containing diets than in those fed low fat-containing diets. In addition, BMJ-S significantly enhanced the serum levels of high-density-lipoprotein cholesterol in animals fed different levels of dietary fat. In Experiment 3, we also examined the effect of dietary BMJ-S on lipid metabolism in rats fed diets with or without cholesterol, and found that BMJ-S markedly decreased hepatic TG levels in rats fed diets without dietary cholesterol; this was not apparent in animals fed diets with dietary cholesterol. With regard to the mechanism(s) responsible for hepatic triglyceride, we found that feeding BMJ-S considerably upregulated the mRNA expression of the mitochondrial carnitine palmitoylacyltransferase 1 (CPT1) enzyme, but there were no effects on enzyme activity in the synthesis and oxidation of fatty acids. These results suggest that the active component(s) in BMJ may be resistant to hydrothermal treatment and is therefore useful as a functional ingredient in dietary supplements to ameliorate lipid-related metabolic disorders.

Production of γ-aminobutyric acid (GABA) and ornithine (Orn) in okara by lactic acid bacteria (LAB) was investigated. Four LAB strains including Lb. brevis NBRC 12005 (12005) were selected as GABA- and Orn-producing strains in GYP medium. However, the LAB produced only slight amounts of GABA and Orn in okara, since okara contained insufficient amounts of Glu and Arg as the precursor amino acids to GABA and Orn, respectively. Therefore, Lb. casei L-14 (L-14) and Lb. casei L-12 (L-12) were used as proteolytic strains, and okara was fermented by mixed culture of L-14/12005 or L-12/12005. After 72 h fermentation by L-14/12005, 89mg/100g of GABA was produced in okara, but Orn did not reach the desired value of 40mg/100g. Combination of the mixed culture of LAB and the addition of Glu and Asp as precursor amino acids was applied in order to increase production of GABA and Orn in okara. When okara combined with 588 mg Glu/100g or 1045mg Arg/100g was fermented by L-14/12005 for 72 h, the amounts of GABA and Orn were 403mg/100g and 216mg/100g, respectively. Moreover, the pH of okara was maintained at below 5, thereby preventing the growth of spoilage bacteria. These results indicated that the combination of mixed culture of LAB and the addition of the precursor amino acids was applicable for the production of GABA and Orn in okara without spoilage.

Changes in quercetin content and antioxidant capacity during cooking were compared between the quercetin-rich onion cultivar ‘Quer-Gold’ and the commonly cultivated ‘Kitamomiji 2000_c12083. Irrespective of the cultivar, the quercetin content and antioxidant capacity were not significantly changed by sautéing, and were higher for ‘Quer-Gold’. Two kinds of onion-rich dishes were prepared, and the quercetin content was compared between the cultivars. The quercetin content of the dishes was higher when ‘Quer-Gold’ was used.

As an introduction for several special issues of this journal regarding research on injured microorganisms (IM), the definition of IM and a brief history, current state and significance, prospects and future problems of IM are overviewed. Although an injured cell is generally considered to be sublethally injured, a model including “semilethal” injuries is also proposed here. In the fields of microorganism preservation and food processing, the occurrence of IM has been recognized as a key factor, and the presence of IM has been one of the critical problems in the detection and enumeration of microorganisms. Studies on IM have recently been activated by increasing the recognition of their significance in sterilization, disinfection and viability measurements. The execution of the so-called “the IM project” supported by the Ministry of Agriculture, Forestry and Fisheries, Japan, as well as the establishment of “the Japanese Research Society for Injured Microbes” may further raise awareness of IM. Nevertheless, there are still unknown and nondescript research areas in the IM world. Eight possible problems in the study of IM are presented and the prospects for resolution of these issues are described.

Injured microorganisms occur during the food manufacturing and are critical in sterilization and preservation, possibly causing food spoilage and foodborne illness. With reference to nonlethal but microbiostatic stress treatment, the abilities of growth, stress response, and tolerance change with time of microbiocidal treatment. In comparison with untreated healthy cells, injured cells possess several physiological characteristics and different sites in the cell are damaged, depending upon the type of the stress. Cell injury are also induced differently by the kind of method of exposure of cells to a stress and several antonymous injury modes are introduced or proposed here. For the detection and enumeration of injured cells, slow type cultivation method and rapid type non-cultivation method are available. Conventional plate counting method in the former has been widely used and fluorescent techniques in combination with flow cytometry as a representative of the latter have recently been concerned.

Heat treatment is commonly used for sterilizing food. The higher the treatment temperature, the greater the sterilization efficiency; however, protein denaturation of food can result. Mild heat treatment may only sublethally injure bacterial cells. Moreover, sublethally heat-injured Salmonella in food can recover under favorable conditions, leading to foodborne illness. To elucidate the molecular mechanism of recovery from heat injury, global changes in gene transcription of Salmonella Typhimurium were investigated. Recovery of the heat-injured S. Typhimurium cells in Tryptis Soy Broth (TSB) resulted in full recovery after 3 h of incubation at 37°C. DNA microarray analysis of 60-min recovering cells revealed an increase in the transcription of 141 genes. Among them, genes of known function involved to various degrees in the recovery were: genes involved in branched-chain amino acid (BCAA) transport (livJ, livH), cell envelope integrity (ddg), heat-shock response (cpxP, rrmJ), phage shock protein (pspA), ribosome modulation factor (rmf), and virulence (sseB) transcriptional regulation (rpoE, rpoH, rseA, rseB, rseC). It was found that supplementation of TSB with BCAA resulted in enhanced recovery of injured cells compared to those recovered without BCAA.