Screening new breeding japonica rice varieties by rice quality, three processing characteristics, and odor characteristics.

Rice's yield, cooking, and sensory quality are primary considerations in selecting new breeding rice varieties, which are determined by the rice eating quality such as processing and flavor characteristics. Thus, in this study, to advance the breed of new superior japonica rice varieties, the differences in the rice quality, processing characteristics, and flavor characteristics between 12 newly-bred varieties (H2-36, H2-42, H2-53, H2-59, H2-63, H2-73, H2-74, H2-79, H2-81, H2-82, H2-89, and H2-91) and 1 commercial variety (Kenyu38) were analyzed. The results indicated that H2-42 has a reasonable length-to-width ratio (1.51), high rice yield, good color, reasonable amylose, protein content, excellent water existence index, accessible storage, and the highest taste value. Electronic nose results showed significant differences in aldehydes, ketones, and alcohols among 13 rice varieties. Aroma analysis results showed that H2-42 had the highest n-hexanal (14.63 µg/kg), (E,E)-2,4-nonadienal (37.24 µg/kg), nonanal (19.93 µg/kg), and decanal (4.81 µg/kg); those were important aroma components in cooked rice. The Pearson correlation analysis showed that hardness, springiness, cohesiveness, trough viscosity, peak time, and pasting temperature were the crucial factors that affected rice quality. According to partial least squares regression analysis, total color change, final viscosity, setback, (E)-2-heptenal, and 2-methyl-undecanol were the most important factors that distinguished the rice quality. In conclusion, H2-42 rice was better apparent quality, processing characteristics, and aroma compounds. Therefore, H2-42 has the potential for identification and promotion. PRACTICAL APPLICATION: The results from this study will provide data support for the cultivation, application, and quality improvement of high-quality rice varieties. In addition, it gives new ideas and methods for studying rice eating quality.

Fingerprinting of Volatile Organic Compounds for the Geographical Discrimination of Rice Samples from Northeast China.

Rice's geographic origin and variety play a vital role in commercial rice trade and consumption. However, a method for rapidly discriminating the geographical origins of rice from a different region is still lacking. Therefore, the current study developed a volatile organic compound (VOC) based geographical discrimination method using headspace gas chromatography-mass spectrometry (HS-GC-MS) to discriminate rice samples from Heilongjiang, Jilin, and Liaoning provinces. The rice VOCs in Heilongjiang, Liaoning, and Jilin were analyzed by agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the optimum parameters for headspace solid phase microextraction (HS-SPME) involved the extraction of 3.0 g of rice at 80 °C within 40 min. A total of 35 VOCs were identified from 30 rice varieties from Northeast China. The PLS-DA model exhibited good discrimination (R2 = 0.992, Q2 = 0.983, and Accuracy = 1.0) for rice samples from Heilongjiang, Liaoning, and Jilin. Moreover, K-nearest neighbors showed good specificity (100%) and accuracy (100%) in identifying the origin of samples. In conclusion, the present study established VOC fingerprinting as a highly efficient approach to identifying rice's geographical origin. Our findings highlight the ability to discriminate rice from Heilongjiang, Liaoning, and Jilin provinces rapidly.

Aroma compounds identified in cooked meat: A review.

Early reviews focused on volatile compounds in cooked meat or meat products by GC-MS analysis. However, actually only a small number of odor-active activities, i.e., odorants, play roles in meat aroma. This review summarized in total 332 odorants identified in thermally cooked meat species (e.g., stewed pork) in the recent 40 years by GC-O through the search of relevant literatures. They included l57 compounds from the lipid degradation, 98 compounds from the Maillard reaction, 18 compounds from the interaction of the lipid degradation and the Maillard reaction (lipid-Maillard interaction), and 59 compounds from other sources, while the formation mechanisms are discussed based on the recent developments. Overall, the aliphatic aldehydes had the greatest number, followed by sulfur-containing compounds, nitrogen-containing heterocyclic compounds, oxygen-containing heterocyclic compounds, ketones, alcohols, etc. The frequently potent odorants in different cooked meat species are the short-chain aliphatic aldehydes of C6-C10 carbons and 1-oceten-3-ol (or 1-octen-3-one) and sulfur-containing or nitrogen-containing heterocyclic compounds. PLS-DA analysis suggested variation of odorants among the cooked beef, pork, poultry, and sheep was more due to the lipid degradation than the Maillard reaction, and marginally due to the lipid-Maillard interaction. This review can be used as guidance in improving flavor of cooked meat and meat flavorings.

Changes in oral processing parameters of three rice varieties.

Mastication and saliva addition affects the formation of a bolus, directly playing a key role in people's eating enjoyment. However, the specific changes of oral physiological parameters and bolus moisture content in the oral processing of rice have not been studied in detail. Thus, in the present study, salivary flow rate, salivary secretion, chewing frequency, and bolus moisture content during oral processing of three rice varieties (japonica rice, indica rice, and glutinous rice) were fully investigated. The differences among different rice and changes among different oral processing stages (25%, 50%, 75%, and 100%) were analyzed. Results showed that the swallowing time of glutinous rice was significantly lower than that of japonica and indica rice (p < .05). However, there was no significant difference in the chewing frequency of the three rice varieties throughout the oral processing stages (1.59-1.66 Hz, p > .05). During oral processing, the salivary flow rates for the three kinds of rice decreased significantly (p < .05), from 37.72 ± 4.32 mg/s (0%-25% stage) to 19.83 ± 5.50 mg/s (75%-100% stage). The dry basis moisture content of the bolus increased significantly (p < .05), from 1.53 ± 0.08 (0%) to 1.96 ± 0.02 (100%). In the 75%-100% stage, the amount of saliva secretion for japonica rice was highest, followed by indica rice and glutinous rice (p < .05). At the point of swallowing (100% stage), the dry basis moisture content of all three rice-bolus' was consistent (1.94-1.99, p > .05).

Effect of vitamin B-12 and n-3 polyunsaturated fatty acids on plasma homocysteine, ferritin, C-reaction protein, and other cardiovascular risk factors: a randomized controlled trial.

OBJECTIVES: Vitamin B-12 and n-3 polyunsaturated fatty acids (PUFA) decrease blood homocysteine (Hcy) concentrations. However, the combined effect of these nutrients on Hcy and ferritin, and C-reactive protein is limited and inconclusive. The objective was to examine the synergistic effect of vitamin B-12 in combination of n-3 PUFA on plasma Hcy, ferritin, and other biochemical markers. METHODS: In a randomized controlled trial, thirty eligible subjects were randomly divided into three groups, and assigned to receive 1000 µg of vitamin B-12, 2 g fish oil, or 1000 µg vitamin B-12 and 2 g fish oil, respectively, for 8 weeks. Plasma phospholipids (PL) fatty acids and biochemical markers were determined. This study was registered under ClinicalTrials.gov Identifier: NCT01762072. RESULTS: Plasma PL 20:5n-3, 22:6n-3 and n-3 PUFA was increased after 4 and 8 week supplementation of fish oil, and vitamin B-12+fish oil. Plasma concentrations of triacylglycerol, uric acid, C-reactive protein, and ferritin were significantly decreased after 4 and 8 week supplementation of fish oil, and vitamin B-12+fish oil. In all groups, significant changes in plasma Hcy were observed during the study period. Vitamin B-12, fish oil, and vitamin B-12+fish oil supplementation lowered plasma Hcy concentrations by 22%, 19%, and 39%, respectively. CONCLUSIONS: The combination of vitamin B-12 and fish oil has a synergistic effect on lowering plasma concentrations of Hcy.

Black tea consumption and serum cholesterol concentration: Systematic review and meta-analysis of randomized controlled trials.

BACKGROUND & AIMS: The results of randomized controlled trials in relation to the effect of regular black tea consumption on serum cholesterol concentration were inconsistent. We aimed to investigate and quantify the effect of black tea consumption on serum concentrations of total, LDL and HDL cholesterol. METHODS: We systematically searched and identified relevant literatures in PubMed, Scopus and the Cochrane Library. Inclusion and exclusion of studies, data extraction, quality assessment and meta-analysis were conducted according to the PRISMA statement. RESULTS: Ten eligible studies with 411 participants were identified in the present meta-analysis. No significant heterogeneity was found between studies. Consumption of black tea significantly reduced LDL cholesterol concentration (-4.64 mg/dL; 95% CI: -8.99, -0.30 mg/dL; P = 0.036). No remarkable change was detected in total cholesterol (-2.04 mg/dL; 95% CI: -6.43, 2.35 mg/dL; P = 0.363) or HDL cholesterol (-1.15 mg/dL; 95% CI: -3.04, 0.75 mg/dL; P = 0.236). Subgroup analysis showed that the lowering effect on LDL cholesterol was more effective in subjects with higher cardiovascular risk. CONCLUSIONS: Black tea consumption significantly lowered serum concentration of LDL cholesterol, especially in subjects with higher cardiovascular risk. Black tea intake did not impose obvious effect on serum concentrations of total and HDL cholesterol.

Plasma phospholipid polyunsaturated fatty acids and homocysteine in Chinese type 2 diabetes patients.

The main aim of the present study was to investigate the plasma phospholipids (PL) fatty acids status and its association with plasma Hcy in patients with type 2 diabetes mellitus (T2DM). One hundred and four T2DM (aged 57.3±13.4 y) and 150 healthy subjects (aged 48.4±8.7 y) were recruited. Plasma Hcy and PL fatty acids were determined by standard methods. Plasma Hcy concentration in T2DM was significantly higher than that in healthy subjects (p<0.001). The prevalence of hyperhomocysteinemia was significantly higher in T2DM (36.54%) than that in healthy subjects (17.32%) (p=0.012). Plasma PL 20:4n-6 (r=0.303, p=0.012), 22:5n-3 (r=0.312, p=0.01), total PUFA (r=0.303, p=0.012), n-6 PUFA (r=0.261, p=0.032) were significantly positively associated with plasma Hcy concentration in T2DM. While, plasma PL n-3:n-6 PUFA (r=-0.400, p=0.046) was negatively associated with plasma Hcy in T2DM. In healthy subjects, plasma PL 22:6n-3 (r=-0.201, p=0.042) was negatively associated with plasma Hcy. In addition, plasma PL 22:6n-3 (r=0.193, p=0.044) and 22:5n-6 (r=0.234, p=0.038) were significantly negatively associated with plasma vitamin B-12 in healthy subjects. Our results suggested that increased plasma Hcy levels in T2DM associated with low n-3:n-6 ratio intake. We suggest that T2DM increase their long chain n-3 PUFA intake from fish or fish oil while decrease n-6 PUFA intake.