Rice production, despite its important role in food security, could bring about environmental problems such as methane emissions and polluting water resources. To decrease such negative environmental impacts, the co-culture of rice with ecologically friendly aquatic animals such as crabs has shown promising results. However, there are still serious concerns about the proper implementation of rice co-culture systems. Having considered rice-crab systems, crab stock density and the amount of crab feed, among others, are two important factors which regulate the performance of the system and the associated environmental pollution. However, their optimal values and their underlying relationship with enviro-economic parameters (e.g. methane emissions, nitrous oxide emissions, ammonia volatilization, yield, N uptake, nitrate in drainage water, and profit) have not been scrutinized yet. Accordingly, a set of farm experiments has been performed to measure enviro-economic parameters under mono- and co-cultivation of rice. Moreover, the attempts were made to explore the underlying correlations between crab stock density and the amount of crab feed as two independent variables and measured parameters such as yield and greenhouse gas emissions. Furthermore, an appropriate optimization model was developed to find the optimal crab density and crab feed in order to minimize the environmental pollution and maximize crab and rice yield as well as net profit. At the end, a farm survey was also conducted to evaluate the shortages in co-culture systems. The results showed that, under optimal rice-crab co-culture system, the improvements in nutrient uptakes ranged from 5.2% to 23.3%, with the lowest for Zn uptake and the highest for N uptake. Under such circumstances, 355% lower global warming impact would be attained compared to rice mono-culture showing a significant contribution to greenhouse gas mitigation. Furthermore, farmers would benefit from 122% higher profit under co-culture systems. The results achieved herein also have policy implications because it would help to decrease national greenhouse gas emissions and avoid deterioration of water resources while help farmers to ensure earning a high profit.

The particular effect of 4 kinds of amino acid and peptide-rich food material (APRM) containing different charged amino acid contents on the gelatinization and retrogradation behavior of potato starch granules and on the water-vaporization behavior was analyzed by differential scanning calorimetry, rapid viscoanalysis, x-ray diffractometry, thermal gravimetry-differential thermal analysis, and pulsed NMR. APRM with a high-charged amino acid content produced unique gelatinization and retrogradation behavior in terms of an elevated gelatinization temperature, reduced viscosity, higher setback, and lower retrograded starch melting enthalpy. The recovered x-ray diffraction intensity decreased with increasing charged amino acid content. APRM with high-charged amino acid content could provide an improved paste having easy vaporization of external water in the swollen starch granules due to the reduced swelling.

BACKGROUND: Partition coefficients give an indication of the retention of aroma compounds by the food matrix. Data in the literature are obtained by various methods, under various conditions and expressed in various units, and it is thus difficult to compare the results. The aim of the present study was first to obtain gas/water and gas/matrix partition coefficients of selected aroma compounds, at different temperatures, in order to calculate thermodynamic parameters and second to compare the retention of these aroma compounds in different food matrices.RESULTS: Yogurts containing lipids and proteins induced a higher retention of aroma compounds than model gel matrices. The observed effects strongly depend on hydrophobicity of aroma compounds showing a retention for ethyl hexanoate and a salting out effect for ethyl acetate. A small but noticeable decrease in enthalpy of affinity is observed for ethyl butyrate and ethyl hexanoate between water and food matrices, suggesting that the energy needed for the volatilization is lower in matrices than in water.CONCLUSION: The composition and complexity of a food matrix influence gas/matrix partition coefficients or aroma compounds in function of their hydrophobicity and to a lower extent enthalpy of vaporization.