ABSTRACT
Insects represent a sustainable, protein-rich food source widely consumed in Asia, Africa, and South America. Eating Clanis bilineata tsingtauica Mell is common in the eastern part of China. A comparative characterization of nutrients in the meat and epidermis of C. bilineata tsingtauica was performed in this study. The results showed this insect to be high in nutrients, particularly in the epidermis where protein total was 71.82%. Sixteen different amino acids were quantified in C. bilineata tsingtauica, and the ratio of essential to nonessential amino acids in the epidermis and meat was 68.14% and 59.27%, respectively. The amino acid composition of C. bilineata tsingtauica is balanced, representing a high-quality protein source. Eight minerals were quantified in C. bilineata tsingtauica, including four macro and four trace elements. Fe in the epidermis and Zn in the meat were abundant at 163.82 and 299.31 µg/g DW, respectively. The presence of phytic acid impacted the absorption of mineral elements in food. We also detected phytic acid in C. bilineata tsingtauica. The molar ratio of phytic acid to zinc (PA/Zn) in C. bilineata tsingtauica was very low (3.28) compared to Glycine max and Cryptotympana atrata, which indicated that mineral utilization was high. In conclusion, this study confirms that C. bilineata tsingtauica is a highly nutritious food source for human consumption, and the results provide a basis for further consumption and industrialization of this edible insect.
ABSTRACT
The rising atmospheric CO2 concentration affects spikelets development, grain filling process, and rice quality. However, it is unclear that whether such effects are related to grain positions on rice panicle. By using a rice FACE (Free-Air CO2 Enrichment) platform, we grew a japoni-ca rice cultivar Wuyunjing 23, characterized with high yield and good quality, under ambient (Ambient) and elevated CO2 concentrations (+200 µmol·mol-1, FACE). The effects of increased CO2 concentration on spikelet density, grain filling capacity, the appearance and eating quality of rice grains were examined and the association of such effects with grain positions on rice panicle were investigated. The results showed that CO2 enrichment increased grain yield of Wuyunjing 23 by 18.3%. The panicle number per unit land area and filled-grain weight increased by 21.4% and 9.4%, respectively; whereas the number of spikelets per panicle and filled-grain percentage decreased by 9.0% and 2.2%, respectively. The decreased filled-grain percentage of rice grown under FACE treatment was mainly related to the increases of empty-grain percentage in all parts of rice panicle. The decrease of rice spikelets number per panicle by FACE treatment was mainly due to the substantial decrease of surviving spikelets of secondary branches in upper and middle parts of rice panicles instead of other positions. The CO2-induced changes of filled-grain weight and filled-grain percentage were similar among grains located at different positions on rice panicle. FACE treatment reduced the green grain rate and increased the grain length and width, with the grains at different positions on rice papnicle showing similar responses. FACE significantly increased chalky grain percentage by 59% and chalkiness degree by 55%, with the increases for both parameters following the order of primary branchesï¼secondary branches and upper partï¼middle partï¼lower part. FACE treatment slightly increased amylose content while decreased peak viscosity, hot viscosity, breakdown, final viscosity and setback, but most of these effects were nonsignificant. The gelatinization temperature of rice also reduced by 5% under FACE, and the decrease of inferior spikelets was greater than that of superior spikelets. In summary, the yield increase of Wuyunjing 23 under high CO2 concentration was mainly related to the increases of panicle number and individual grain weight, while the panicle size was reduced. Elevated CO2 concentration reduced green grain percentage but increased grain chalkiness, and had little effect on cooking and eating quality. The grain positions on rice panicle affected the responses of spikelets development, grain filling capacity and grain quality of rice to elevated CO2 concentration, but the effects varied across different indices.
Subject(s)
Oryza , Amylose , Carbon Dioxide , Edible GrainABSTRACT
The increase of ground-level ozone concentration significantly reduces rice yield, but its effect on grain quality in association with the positions on a panicle was largely unknown. The effects of ozone stress on amylose content and RVA profile of rice grains located at different positions of panicles were studied by using a sunlit gas fumigation platform. Eight varieties representing different types of rice were fumigated under ambient (9 nL·L-1) or elevated ozone (100 nL·L-1) concentrations from transplanting until maturity. The results showed that elevated ozone treatment significantly reduced amylose content, maximum viscosity, hot viscosity, breakdown and cold viscosity by 5.9%, 7.6%, 5.9%, 11.6%, 2.9%, respectively, but increased the setback and gelatinization temperature by 24.9% and 1.0%. There were significant differences among varieties for amylose content and all parameters in RVA profile. The grains located at different positions on a panicle differed in amylose content, maximum viscosity, hot viscosity, breakdown and cold viscosity. The superior grains located at the upper part of a panicle had the highest value and the inferior grains located at the lower part of a panicle had the lowest value. However, the setback in RVA profile showed a different trend, with the superior grains having the lowest setback but inferior grains having the highest setback. In most cases, there were significant interactive effects of ozone by year or ozone by variety on amylose content and RVA profile. No significant ozone by grain position interaction on RVA profile was found, although the responses of superior grains to ozone stress was slightly smaller than those of inferior grains or grains located at the middle part of a panicle. The results demonstrated that ozone fumigation of 100 nL·L-1 during rice growing season deteriorated rice quality, with the magnitude of deterioration varying with growth seasons and varieties and little impacts of grain positions on a panicle.
Subject(s)
Oryza , Ozone , Amylose , Starch , ViscosityABSTRACT
Light and carbon dioxide (CO2) are two essential components for plant photosynthesis. To understand the effects of elevated CO2 concentration on photosynthetic characteristics of hybrid rice under different light conditions, two hybrid rice varieties (YLY900 and YY538) were grown in the field using a free-air CO2 enrichment facility (FACE) in 2017 with two CO2 concentration treatments (ambient CO2 and elevated 200 µmol·mol-1 above ambient CO2), the photosynthesis traits of top full expansion leaves were measured in both sunny and cloudy days at jointing and grain filling stages. Elevated CO2 increased net photosynthetic rate (Pn) of two rice varieties. The increase in sunny days (31%) was greater than in cloudy days (21%), and the increase at jointing stage (37%) was greater than at grain filling stage (21%). There were significant interactions between CO2 with weather, and between CO2 with growth stage. Water use efficiency (WUE) of leaves in response to elevated CO2 showed the similar trend as Pn. Elevated CO2 decreased stomatal conduc-tance (gs) and transpiration rate (Tr), and the decreases in sunny days were greater than that in cloudy days. The Pn, gs, Tr, WUE and stomatal limit (Ls) measured in cloudy days were significantly lower than that measured in sunny days by 41%, 18%, 41%, 26% and 27%, respectively. Results from the correlation analyses showed that the Pn, gs, and Tr in sunny days were significantly positively correlated with the corresponding parameters in cloudy days. The results indicated that cloudy weather conditions reduced photosynthesis and its response to elevated CO2 of two hybrids rice varieties at middle and late growth stages. Therefore, weather variation should be considered when assess rice yield potential in the future environment.
