Infrared Heating as a Disinfestation Method Against Sitophilus oryzae and Its Effect on Textural and Cooking Properties of Milled Rice

Advances in Environmentally Friendly Techniques and Circular Economy Approaches for Insect Infestation Management in Stored Rice Grains

Rice (Oryza sativa L.) is a staple food for about half of the world's population. Therefore, it is important to search for solutions that minimise losses and production costs for producers and ensure food quality and safety for consumers. Improved methods for the detection and monitoring of hidden infestations are useful for adopting infestation control measures. Chemical methods are used to prevent rice losses due to infestations; changing this situation, however, is of the utmost importance, as it harms the environment and human health. The management of infestation by controlled storage conditions, namely temperature and atmosphere composition and the use of current fossil-based packaging with modified atmospheres, is well recognised. The use of environmentally friendly solutions is promising, but it is necessary to perform a life-cycle assessment and cost analysis to evaluate their effectiveness. According to the principles of circular economy, the integration of the best-selected treatments/solutions for insect management, along with the use of biopackaging from rice by-products are recommended. This review describes the methods of detection and control of infestation as well as several promising alternatives to chemical treatments; however, more research is needed in order to obtain effective technological solutions that can be applied at an industrial scale.

Combined Heat and Mass Transfer Associated with Kinetics Models for Analyzing Convective Stepwise Drying of Carrot Cubes

Stepwise drying is an effective technique that promotes energy saving without additional capital cost. The stepwise drying mode was investigated for energy consumption and dried product qualities using a coupled heat and mass transfer model associated with kinetics equations of volume shrinkage and degradation of β-carotene in carrot cubes. Simulations were performed using a finite element method with extension of a chemical species transport. Validation experiments were carried out under constant drying modes at 60 °C, 70 °C and 80 °C using a lab-scale convective hot air dryer. The verified models were subsequently employed to investigate the effects of two step-up drying modes (60 to 70 °C and 60 to -80 °C). The optimal drying condition was determined using the synthetic evaluation index (SI) with criteria of high specific moisture evaporation rate (SMER), low shrinkage ratio and β-carotene degradation. Simulated results showed comparable agreement with experimental data of moisture content, shrinkage ratio and β-carotene ratio. Step-up drying of 60 to 70 °C gave the highest SMER of 0.50 × 10^-3 kg of water evaporated per kWh, while the operation at constant temperature of 80 °C gave the lowest value of 0.19 × 10^-3 kg of water evaporated per kWh. Model-predicted results showed less shrinkage of carrot cubes, but higher degradation of β-carotene under step-up drying compared to single-stage drying under temperature of 60 °C. Based on the highest SI value (0.36), carrot cubes were optimally dried under step-up mode of 60 to 70 °C.

Effects of infrared heating as an emerging thermal technology on physicochemical properties of foods

Infrared (IR) radiation is part of an electromagnetic spectrum between the ultraviolet and microwave regions. IR radiation impacts the surface of the food, generating heat that can be used as an efficient drying technique. Apart from drying, IR heating is an emerging food processing technology with applications in baking, roasting, microbial inactivation, insect control, extraction for antioxidant recovery, peeling, and blanching. Physicochemical properties such as texture, color, hardness, total phenols, and antioxidants capability of foods are essential quality attributes that affect the food quality. In this regard, the main objective of this review study was to highlight and discuss the effects of IR heating on food quality to expand its food applications and commercial adoption. The fundamental mechanisms, type of emitters, and IR processing parameters are discussed in this review to explore their impacts on food quality. Infrared heating has been shown that the appropriate operating conditions (distance, exposure time, IR power, and temperature) with high heat transfer, thus leading to a shorter drying time. Besides, IR heating used in food processing to improve food-surface color and flavor, it also enhances hardness, firmness, shrinkage, crispiness, and viscosity. Meanwhile, antioxidant activity is enhanced, and some nutrients are retained.

Effects of Different Infra-Red Irradiations on the Survival of Granary Weevil Sitophilus granarius: Bioefficacy and Sustainability

Sitophilus granarius (L.) is an important pest of stored grain worldwide. In recent years, sustainable methods against it have received attention as grain stock protective means. Our aim was to obtain information about the efficacy of infrared irradiation (IR) against S. granarius in laboratory conditions. The change in adult-activity and median lethal dose (LD50) triggered by IR in S. granarius was examined. The insecticidal efficacy in the infested grains was also analyzed at 12, 24, 48, and 72h following exposure to IR (250W), and the progeny-production was assessed 45 days upon the treatment. Based on our findings, total mortality ensued in a grain stock of 50 g at 412 s and a for 100 g grain at 256 s. A significant increase in S. granarius mortality could be observed in the higher grain weight regime, which can be accounted for by the higher heat-absorbance of objects with higher weight. The activity of pests immediately after the beginning of IR increased and subsequently became moderated. The observation of activity-peak brought about by irradiation contribute to the optimization of chemical intervention. This treatment could provide an effective and sustainable technique in integrated pest management.

Influence of microwave heating as accelerated aging on physicochemical, texture, pasting properties, and microstructure in brown rice of selected Indian rice varieties

Most of the population does not prefer to consume brown rice because of its strong nutty and chewy texture imparted by bran and germ. The present study has been undertaken to investigate the influence of accelerated aging through microwave (MW) heating at a lower and higher MW power levels of 950 and 1,400 W for 72 and 91 s to observe the changes in physicochemical, texture, pasting properties, sensory attributes, and microstructure of selected rice varieties (Sona masuri and RNR-15048) stored as brown rice for 6 months. The results revealed a significant decrease in moisture, amylose, free fatty acids (FFAs) with changes in color (L*, a*, and b* values) in both the varieties treated at 1,400 W for 91 s. An increase in kernel elongation ratio, water uptake, and a decrease in cooking time and solid loss was noted in both the varieties. After cooking, the texture of both the varieties showed an increase in hardness with reduced stickiness at both lower and higher MW power levels of 950 W for 72 s and 1,400 W for 91 s compared to untreated brown rice with an improved porous structure when observed under SEM analyzer followed by better water absorption and organoleptic properties after cooking. The reduction in final viscosity has been noted in both the varieties at 1,400 W for 91 s due to the binding of FFA with starch. Thus, the MW power level of 950 W for 72 s and 1,400 W for 91 s showed the better results for short-grain varieties like Sona masuri and RNR-15048 stored as brown rice.

Improvement of cooking quality of germinated brown rice attributed to the fissures caused by microwave drying

Germinated brown rice (GBR) contains rich bio-active components, but has poor edible quality. To improve the cooking quality of GBR, fissure generation in kernels caused by microwave drying were investigated considering cooking properties, microstructure and textural attributes. The microwave intensity had significant effects on the fissure percentage of GBR, and microwave intensity of 3-4 W/g may be suitable for the microwave drying of GBR based on the distribution of fissure percentage for the GBR. The fissures of GBR caused by microwave drying provided the suitable penetration routes of water into GBR kernel. Appropriate fissure amount in range of 3-4 in GBR kernels were conducive to increase its cooking quality and rice taste due to the moderate water absorption and starch gelatinization. The results present a new viewpoint from the perspective of fissures inside grain kernels to evaluate the drying quality of cereal materials such as GBR.