Portable glucose meter (PGM) has played vital roles in the field of medicine, with advantages of accurate and quantitative results, portability, easy operation, and low cost. Recently, more and more researchers have extended the application of PGM in detecting foods contaminations. In this paper, a review of the application of PGM based on target recognition elements, such as antibody–antigen reaction, molecularly imprinted polymer, nucleic acid hybridization, enzyme recognition, and click chemistry, and amplification strategies in food safety and contaminant analysis are described in detail. The future development of the application of glucose meters in food safety supervision is also discussed.

For rare sugars to be used in fermented foods, their effect on microorganisms used in soy sauce brewing must first be determined. Here, when soy sauce-brewing microorganisms were cultured with a mixture of four rare sugars (d-allulose, d-allose, d-tagatose, and d-sorbose) with d-glucose, growth was not inhibited when the percentage of each rare sugar did not exceed 60% of the carbon source. d-Tagatose was not inhibitory, even at 100% of the carbon source, and it had the same effect as d-glucose on lactic acid fermentation by Tetragenococcus halophilus. To confirm soy sauce can be brewed with rare sugars, we conducted a small-scale brewing study with a rare sugar syrup (RSS). After aerobic fermentation by the yeast, the relative composition of each rare sugar remaining in the brew was 95% allulose, 34% allose, 68% tagatose, and 84% sorbose of the respective original concentration. Analyses of the final product found that acidic bitterness and acidic bitter aftertaste of the soy sauce were suppressed compared to the control, and this was attributed to a decrease in the amount of basic amino acids, which might be related to bitterness, during brewing.

In the course of screening for antioxidant agricultural products in Shizuoka Prefecture, Japan, we found that Akebia trifoliata Koidz fruit had a high activity. Furthermore, we found that the peel of A. trifoliata showed remarkable antioxidant activity compared to other parts of the fruit. We isolated seven known phenylpropanoids, including caffeoylquinic acids from the peel of A. trifoliata: 5-O-caffeoylquinic acid (1), 4-O-caffeoylquinic acid (2), 3-O-caffeoylquinic acid (3), 4,5-di-O-caffeoylquinic acid (4), 3,5-di-O-caffeoylquinic acid (5), calceolarioside B (6), and (4-hydroxyphenyl)-ethyl-6-O-(E)-caffeoyl-β-d-glucopyranoside (7). These isolated compounds were found to contribute to the antioxidant activity of the peel, with 6 exhibiting the strongest activity amongst them. Quantitative analyses showed that 6 is abundant in the peel of A. trifoliata. Therefore, the peel of A. trifoliata can be effectively used as a functional material with antioxidant activity.

The aim of this study was to investigate the protective effect of polyphenol extract from Highland barley (HBPE) on cisplatin (CDDP)-induced oxidative damage and mitochondrial damage in rat kidney. The experimental rats were divided into control group, CDDP group, HBPE (600 mg/kg) group, CDDP+HBPE (150 mg/kg) group, CDDP+HBPE (300 mg/kg) group and CDDP+HBPE (600 mg/kg) group. Rats in each group were intragastrically fed with normal saline and corresponding dose of HBPE for 21 d. On the 16th day, CDDP group and CDDP+HBPE group were injected intraperitoneally with CDDP (7.5 mg/kg), and the other groups were injected with the same amount of normal saline. On the 22nd day, the rats were killed and blood samples were taken to detect the contents of blood urea nitrogen (BUN) and creatinine (CrE) in serum, and calculate the kidney index. The kidney samples were used for the measurement of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), hexokinase (HK), and processed for histopathological examinations. The results showed that HBPE improved the abnormalities of serum CrE, BUN, antioxidant and carbohydrate metabolic enzymes in kidney induced by CDDP. HBPE can also reduce the degeneration of renal tubules and glomerular atrophy. Therefore, HBPE has a significant protective effect on oxidative stress injury and mitochondrial damage induced by CDDP in rats.

As the average longevity of humans increases, the number of patients with osteoporosis has also increased. Chemoprevention for osteoporosis, especially through food intake, may extend the healthy life expectancy. We previously reported that kudzu (Pueraria lobata) vine ethanol extract (PVEE) in the diet (20 mg/kg body weight/d) suppresses bone resorption and prevents bone loss in ovariectomized mice. However, experiments with lower PVEE concentrations are necessary to determine whether PVEE is a suitable functional food resource to improve osteoporosis. This study thus examined the effects of PVEE intake (2 or 5 mg/kg body weight/day, approximately 0.07 or 0.17 mg PVEE isoflavone/d/mouse) for 6 months. The dose was calculated on the basis of the recommended daily isoflavone allowance in Japan. Both 2 and 5 mg PVEE successfully prevented ovariectomy-induced bone loss in mice. These results indicated that PVEE was effective at these doses. Thus, PVEE has the potential to be a promising resource for osteoporosis-preventing functional foods.

The optimal preparatory conditions identified using random-centroid optimization revealed that the maximum hydroxyl radical antioxidant activity (63.4 ± 4.8 µmol of gallic acid equivalent/g of protein) was achieved at 70 °C; relative humidity, 45%; reaction time, 47.92 h; and glucose to soybean 11S globulin ratio, 10.66:1 (w/w). The average particle size of the oil-in-water emulsions prepared using optimally glycated, unreacted, and native soybean 11S globulin was 1.68 ± 0.11, 1.81 ± 0.18, and 2.36 ± 0.42 µm, respectively. The emulsion stability of the optimally glycated and unreacted soybean 11S globulin was superior to that of native soybean and did not exhibit complete separation after four weeks. When a sufficient amount of optimally glycated soybean 11S globulin was present in the emulsion, oil oxidation was significantly suppressed, suggesting the potential use of optimally glycated soybean 11S globulin as an antioxidant.

An aminopeptidase was purified from Proteax, a food-grade commercial enzyme reagent derived from Aspergillus oryzae that showed the highest debittering effect on casein hydrolysates among nine such reagents, and its enzymatic characteristics and debittering activities were investigated. Treatment with the enzyme, identified as leucine aminopeptidase A (LapA), on pepsin-degraded casein and cod protein solutions reduced their bitterness and increased the amount of free hydrophobic amino acids such as leucine, valine, isoleucine, and phenylalanine, as well as arginine, tyrosine, and threonine. These results indicated that LapA preferentially released hydrophobic amino acid residues at the amino terminus of peptides including bitter-tasting peptides and reduced the bitterness of protein hydrolysates.

Isorhamnetin (3′-methylquercetin) is one of the major metabolites of quercetin. We hypothesized that Eubacterium limosum JCM6421^T transforms isorhamnetin back to quercetin and the type of sugar affects short-chain fatty acid production by E. limosum JCM6421^T. Anaerobic broth (0.2 mL) containing this bacterium was added to the isorhamnetin solution and anaerobically incubated for 8 and 24 h. Additionally, E. limosum JCM6421^T was anaerobically incubated with various 2 µL-sugar solutions for 24 h and short-chain fatty acid production by this bacterium was measured. Quercetin was produced by anaerobic incubation of isorhamnetin with E. limosum JCM6421^T. Its production increased with an increase in incubation time from 8 to 24 h. Mannitol was the ideal sugar for butyric and acetic acid production by E. limosum JCM6421^T among the investigated sugars. We discovered that E. limosum JCM6421^T produces quercetin from isorhamnetin.