A decade has passed since the nuclear power plant accident, caused by the Great East Japan Earthquake, occurred on March 11, 2011. The major radionuclides that were released as a result of the nuclear accident and that contaminated the domestic agricultural, livestock, and fishery products were radioactive iodine (131I) and radioactive cesium (134Cs and 137Cs). The contamination by 131I with a short half-life of 8 days subsided within months of the nuclear accident. On the contrary, radioactive cesium, especially 137Cs, which has a long half-life of 30 years, persists as a long-term contaminant. The level of radioactive substances in domestically produced food, including agricultural, livestock, and fishery products, are monitored using the inspection based on guidelines established by the Nuclear Emergency Response Headquarters and controlled rigorously. In addition, understanding the behavior of radioactive cesium during the processing/cooking of domestic food products will aid in risk management for food safety and risk communication to consumers. Several such studies have been conducted since the nuclear accident. Here, we review the radioactive cesium levels in domestic agricultural, livestock, and fishery products and outline the observations on its behavior in processed/cooked products after the nuclear accident in 2011.
Abstract: In recent years, sous vide (SV), or vacuum cooking, has been used to prepare foods and beverages by both food industries and restaurants worldwide. SV is considered a transformation of traditional cooking into a more nutritionally, healthier cooking. SV has the advantages in precise control of heating temperature and time, to improve quality, color, flavor, and nutritional value of food. In this review, we first describe the research progress in SV technology, concerning food quality (e.g., texture, color, flavor), nutrients (e.g., lipids, proteins, vitamins) food safety, and feasibility. Meanwhile, we also address the challenges and perspectives of this new food processing technique.
Wheat bran is abundant in dietary fiber, and an important indicator for evaluating the dietary fiber is the soluble dietary fiber (SDF) content. In this study, we analyzed the effect of steam explosion (SE) treatment on the SDF content of wheat bran. The parameters, including steam pressure, residence time, and mesh size were optimized, and it was found that the content of total SDF in wheat bran after SE treatment could be increased from 18.88% to 40.32%. The SDF characteristics from raw wheat bran and SE-treated wheat bran were investigated. The results show that the molecular weight of SDF decreased after SE treatment, and the SDF surface became disintegrated. In addition, the thermodynamic characteristic of SDF was improved after SE treatment, and similar functional groups were found to those SDF from raw wheat bran. These effects could potentially improve the physicochemical properties of SDF and increase the application value of wheat bran.
The phase behavior of a mixture of rapeseed and soybean oils during cooling and heating was observed through differential scanning colorimetry (DSC). The mixture was cooled from 50 to −80 °C at 4 °C/min and heated from −80 to 50 °C at 2 °C/min. A polymorphic transition was observed during heating when the mixture contained soybean oil at a weight fraction of ≥ 0.7. Comparing the results presented herein with those for a binary mixture of high-purity triacylglycerols (TAGs) indicated that some peaks could be ascribed to the formation and melting of crystals rich in triolein and trilinolein. The total released or absorbed energies during cooling or heating were calculated from the DSC curves and were affected by the polymorphic transition and TAG interactions.
Various types of sugar products were classified by measuring their mineral compositions. As a result, the sugar products could be classified according to the results of principal component analysis (PCA) and cluster analysis of the mineral compositions. It also became possible to distinguish between kokuto (black sugar) from China and kokuto from Okinawa, which were classified into the same group in the PCA using a taste sensing system in the authors' previous report. These results agree with the previous report showing that the synthetic variables obtained by PCA of taste information values by the three sensors of a taste sensing system were correlated with the kokuto taste indexes, which indicate the taste intensity of kokuto, and that sugar products can be broadly classified into three groups. Consequently, the taste of sugar products can be now predicted from their mineral compositions.
In the present study, we examined the use of lactic acid bacteria as a starter for the production of pickled luffa. A starter culture of lactic acid bacteria was added to a brine containing 1% of glucose and NaCl that was used to make pickled luffa. Fermentation at 10 °C for 7 days resulted in an increase in the γ-aminobutyric acid content of pickled luffa in all the strains. In Lactococcus lactis NH-61, pickled luffa had good taste and its browning was suppressed. Lactobacillus sakei MMF-LS151 was excellent in regarding the acidity of brine, but led to the browning of pickled luffa. To the best our knowledge, this is the first report on the production of good tasting low-salt pickled luffa.
During frying of food in oil, the high oil temperature allows water evaporation to occur inside the food due to the rapid heat transfer, and the evaporated water is replaced by oil. Moisture loss and oil absorption play an important role in the deep-frying process, providing a unique palatability and sensory characteristics to the food products. Rapeseed oil is often used as for frying. Extra virgin olive oil (EVOO) is also commonly used in kitchens. This study aimed to compare the moisture loss and oil absorption in French fries deep-fried in various combinations of these oils. Foods deep-fried in EVOO exhibited higher moisture loss and oil absorption than those deep-fried in rapeseed oil. Blending of EVOO with rapeseed oil enhanced moisture loss and oil absorption and also reduced the amount of acrolein formed during deep-frying. These results suggest that EVOO gives greater palatability to deep-fried foods and shows less deterioration of the frying oil than rapeseed oil.
We aimed to establish an objective method to evaluate the quality of dried sea cucumber products. Clearness of papillae on the body wall affects the quality and commercial value of this luxury seafood. Unfortunately, an objective method for evaluating papilla clearness remains to be developed. We digitalized clearness of papillae from dried sea cucumber products images using TouchDeMeasure. This software application was developed by the authors. Using this tool, we measured body length (BL), total perimeter including all papillae (TP), and ellipse perimeter excluding the papillae (EP). Results showed that TP/BL, TP/EP, and (TP-EP)/BL values for a clear papilla were significantly higher than those for an unclear papilla. Additionally, we confirmed that these parameters corresponded with the grading levels used by a connoisseur. These experimental results show that our method digitally analyzes the clearness of papillae to evaluate the quality of dried sea cucumber products.
The objective of this study was to develop an optimal processing technique capable of reducing antinutrients to acceptable levels, retain nutrients and functional values of avocado seeds for human consumption. Different processing conditions for probiotic fermentation, boiling and soaking techniques were studied to establish optimal processing conditions for the seeds. The antinutrients, antioxidant activity, total phenolics and selected nutrients of avocado seeds were analyzed using analytical standard methods. All processing techniques significantly (p < 0.05) reduced over 50% of antinutrients. The highest total phenolics and antioxidant activity (IC50) were 33.3 mgGAE/g and 0.8 mg/mL respectively which were observed at a fermentation temperature of 37 °C. Soaking and boiling reduced the analyzed minerals to about 30% whereas probiotic fermentation retained 100% of minerals analyzed, ascorbic acid and α-tocopherol. Moreover, probiotic fermentation demonstrated the best results in comparison to boiling and soaking thus, considered as an optimal processing method for improving nutritional and functional values of avocado seeds.
Naked oat was used to develop a kind of fresh extruded rice-shaped kernels (FER) by extrusion technology, and natural selenium-enriched rice flour was added to solve the problems of irregular shape, dark color and hardness of extruding pure naked oat. Results showed that the addition of rice flour had significantly improved the product properties of FER including shape, color, transparency and texture. Compared to the control (CK), the contents of protein, fat and total dietary fiber (TDF) in FER decreased obviously (p < 0.05) with rice flour addition. The oat-rice FER's shape turned to plump and appearance was acceptable, and had higher water uptake ratio (WUR), elongation ratio and solid loss (SL) than CK. The hardness of FER significantly decreased (p < 0.05) after adding rice flour, and FER with 35% rice flour ratio (35% FER) had the highest sensory evaluation score (7.31 out of 9). Then 35% FER was selected for further vitro activity study, and result showed that bile acid binding rates of 35% FER were stronger than normal natural rice.
We investigated the effects of dietary porphyran, an indigestible sulfated polysaccharide and the main component of nori, Porphyra yezoensis, and glycerol galactoside (GG; floridoside: 2-O-glycerol-α-D-galactopyranoside, and isofloridoside: 1-O-glycerol-α-D-galactopyranoside), which is abundant in low quality discolored nori and has prebiotic activity, on the concentration of immunoglobulin A (IgA) and microbiota in the cecum of mice. Porphyran increased the IgA concentration and contents in the cecum more than 2-fold. GG alone had little effect on these indices, but synergistically enhanced the IgA-elevating effect of porphyran greatly. Porphyran and GG both altered the cecal microbiota, and an interactive effect of porphyran and GG on the cecal microbiota was observed. Therefore, GG and porphyran are considered to have a synergistic effect on the intestinal immune system through the intestinal microbiota and their metabolites.
Volatile compounds in three mango (Mangifera indica L.) cultivars (Irwin, Carabao, and Nam Dok Mai) were investigated using aroma extract dilution analysis (AEDA) and AROMATCH. The AROMATCH analysis technique was applied to evaluate odor interactions: the relationships between a natural aroma and volatile compounds separated by gas chromatography (GC). As a result, 41 odor-active compounds were detected, 36 compounds of which were identified. Three volatile compounds (3-carene oxide, 4-acetoxy-2,5-dimethyl-3(2H)-furanone, and (Z)-6-dodecen-4-olide) were identified in mango for the first time. The flavor dilution (FD) factor for (Z)-6-dodecen-4-olide differed obviously between AEDA (FD: 243)and AROMATCH (FD: 59049) in Irwin. In addition, 3-carene oxide was described as plastic-like byAEDA but fruity by AROMATCH
Dragon fruit is a prebiotic source of oligosaccharides. This is the first report on a study that evaluates the anti-inflammatory effects of dragon fruit oligosaccharides (DFO) on a macrophage cell line. This experiment evaluated the effects of DFO on both gene and protein expression levels in the inflammatory response of a lipopolysaccharide-induced RAW 264.7 macrophage cell line. The results showed that DFO significantly inhibited prostaglandin-E2, nitric oxide, and tumor necrosis factor-α production. DFO also significantly suppressed the expression of cyclooxygenase-2 and inducible nitric oxide synthase. These results suggest that DFO is a potentially novel ingredient for use as an anti-inflammatory prebiotic for the prevention of inflammation.
The physicochemical properties of recovered protein from Japanese anchovy using salt water treatment and pH-shift processing were investigated and compared. The protein recovery yield was the highest with the acid-aided treatment, followed by the salt water and alkaline-aided treatments. No significant differences were found between minced fish and the recovered protein using salt water treatment in L* value, b* value and Ca-ATPase activity. Moreover, myofibrillar protein extracted from the recovered protein using salt water and acid-aided treatments exhibited lower surface hydrophobicity than that using the alkaline-aided treatment. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated a greater concentration of myosin heavy chain and actin in the recovered protein by the salt water treatment, while those proteins were degraded in the acid and alkaline-aided treatments. Overall, the results demonstrated that the physicochemical properties of the recovered protein using salt water treatment were superior to those using pH-shift processing.
Wasabi leaf has been reported to show human health benefits without assessment of its safety. This study aims to investigate the mutagenicity, acute and sub-acute toxicity and human trial safety of wasabi leaf extract (WLE). The Ames test was used to assess mutagenicity, while acute and sub-acute toxicity were assessed by oral administration in five-week-old Slc:ICR mice (SPF) and five-week-old Sprague-Dawley (SD) rats, respectively. Human trial safety was further determined in a clinical trial. Twelve healthy subjects, aged 20–64 years and mildly obese (BMI 23.0 to 30.0 kg/m2), were enrolled in the clinical trial, and participants ingested 200 mg WLE daily for 12 weeks. The effect of WLE on fat metabolism was evaluated by visceral fat area (VFA), subcutaneous fat area (SFA), VFA/SFA(V/S) area ratio, body weight, BMI, TG, T-Cho, HDL-C, LDL-C, waist circumference, and body fat percentage. In the Ames test, WLE did not show mutagenicity in the range of 1.2–5000 µg/plate. No acute toxicity was observed in Slc:ICR mice (SPF) administered 5000 mg/kg/day WLE, and no sub-acute toxicity was observed in Crl:CD (SD) rats administered 2500 mg/kg/day WLE. In the human clinical trial, there were no significant differences between the WLE and placebo groups for any outcome measure assessed. Thus, ingestion of 200 mg/day of WLE was demonstrated for the first time to be safe. Taken together, our data on the mutagenicity, acute and sub-acute toxicity and human trial safety of WLE provide the first standard references for wasabi leaf supplement application.
The crude polysaccharides were extracted from the seeds of Toona sinensis using deionized water, and further purified with DEAE-Sepharose CL-6B column to afford STSP-1, STSP-2, STSP-3 and STSP-4. The high efficiency gel filtration chromatography (HPGFC) analysis showed that the average molecular weight of polysaccharides (STSP-2, STSP-3) were 21.4 kDa and 43.7 kDa, separately. Monosaccharide analysis detected arabinose, rhamnose, glucosamine, galactose, glucose, xylose, mannose, glucuronic acid and galacturonic acid. Moreover, their in vitro anticoagulant activities were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) assays. In comparison with the control group(saline), STSP-3 could prolong PT and TT significantly, but not APTT. STSP-3 exhibited potent anticoagulant activity and would be explored as a natural potential anticoagulant.
High-amylose rice elicits a mild glycemic response; however, the effect of cooking condition on the glycemic response remains unclear. We aimed to investigate the effect of pressure-cooker cooking on postprandial glycemic response and eating qualities of the high-amylose rice “Koshinokaori”; and rice cooked in an electric rice cooker (KKE) was compared with that cooked in a pressure cooker (KKP). The intermediate-amylose rice “Koshihikari”, cooked in an electric rice cooker (KHE), was the reference. In ten healthy subjects, blood glucose variation was significantly lower after consumption of KKP (45 to 120 min) and KKE (60 to 120 min) compared to KHE. Incremental area under the curve after KKE and KKP intake was significantly lower than that after KHE intake. While the hardness of KKP was the highest, strength and stickiness were similar for all three samples. The sensory evaluation score of KKP was closer to that of KHE than KKE, indicating that KKP is a better choice for glycemic control.