Stability of vitamin C, color, and garlic aroma of garlic mashed potatoes in polymer packages processed with microwave-assisted thermal sterilization technology

Quality control of cooked rice: Exploring physicochemical changes of the intrinsic component in production

Sensory deterioration exists in marketed cooked rice. The migration and interaction of intrinsic components occur under multiple conditions in each industrial production process and cause relevant physicochemical changes in cooked rice. This review aims to establish a scientific knowledge system of intrinsic component transition and migration in cooked rice kernel during processing to solve qualitative deficiencies in cooked rice products. The main influencing factors of intrinsic component structural change in cooked rice and the quality control points that should be considered are summarized. Further studies are needed to establish proper evaluation standards for cooked rice products to meet the growing consumer demands.

Quantitative Analysis of Genomic DNA Degradation of E. coli Using Automated Gel Electrophoresis under Various Levels of Microwave Exposure

The problem that this study addresses is to understand how microwave radiation is able to degrade genomic DNA of E. coli. In addition, a comparative study was made to evaluate the suitability of a high-throughput automated electrophoresis platform for quantifying the DNA degradation under microwave radiation. Overall, this study investigated the genomic DNA degradation of E. coli under microwave radiation using automated gel electrophoresis. To examine the viable organisms and degradation of genomic DNA under microwave exposure, we used three methods: (1) post-microwave exposure, where E. coli was enumerated using modified mTEC agar method using membrane filtration technique; (2) extracted genomic DNA of microwaved sample was quantified using the Qubit method; and (3) automated gel electrophoresis, the TapeStation 4200, was used to examine the bands of extracted DNA of microwaved samples. In addition, to examine the impacts of microwaves, E. coli colonies were isolated from a fecal sample (dairy cow manure), these colonies were grown overnight to prepare fresh E. coli culture, and this culture was exposed to microwave radiation for three durations: (1) 2 min; (2) 5 min; and (3) 8 min. In general, Qubit values (ng/µL) were proportional to the results of automated gel electrophoresis, TapeStation 4200, DNA integrity numbers (DINs). Samples from exposure studies (2 min, 5 min, and 8 min) showed no viable E. coli. Initial E. coli levels (at 0 min microwave exposure) were 5 × 108 CFU/mL, and the E. coli level was reduced to a non-detectable level within 2 min of microwave exposure. The relationships between Qubit and TapeStation measurements was linear, except for when the DNA level was lower than 2 ng/µL. In 8 min of microwave exposure, E. coli DNA integrity was reduced by 61.7%, and DNA concentration was reduced by 81.6%. The overall conclusion of this study is that microwave radiation had a significant impact on the genomic DNA of E. coli, and prolonged exposure of E. coli to microwaves can thus lead to a loss of genomic DNA integrity and DNA concentrations.

Unlocking the Potential of Microwave Sterilization Technology in Ready-to-Eat Imitation Crab Meat Production

Microwave sterilization is a novel potential sterilization technology to improve food quality. An industrial microwave sterilization system was used to sterilize imitation crab meat under thermal processing intensity F0 = 1, 2, 3. The characteristics of the microwave process, such as heating rate, processing time, and C100, were calculated. In addition, the quality of processed imitation crab meat was investigated. Compared with the conventional retort method, microwave sterilization significantly shortened the processing time of imitation crab meat by 63.71% to 72.45%. Under the same thermal processing intensity, microwave sterilization has demonstrated better results than retort sterilization in terms of water-holding capacity, color, and texture. Furthermore, microwave-treated imitation crab meat ingredients had a greater capacity to bind water molecules and obtained a more appropriate secondary protein structure. In addition, microwave technology can better preserve the unsaturated fatty acids (UFA) of imitation crab meat, which are 9.14%, 1.19%, and 0.32% higher than the traditional method at F0 = 1, 2, 3. The results would provide useful data for the subsequent research and development of ready-to-eat surimi products.

Multi-accelerant approach for rapid shelf-life determination of beverages in polymeric packaging

An effective analysis method with multiple accelerant factors is needed for shelf-life determination and prediction for food products with reduced analysis time. Raising the storage temperature is the most common approach utilized in the conventional accelerated shelf-life test (ASLT) to reduce the shelf-life testing time of food. Oxygen pressure as an accelerant for the shelf-life determination of food products has not been given much attention even though it has shown a negative impact on food shelf-life. Combining oxygen pressure and temperature as accelerants has the potential to further reduce the overall analysis time compared to the ASLT. This study focuses on the effects of applying oxygen pressure and temperature as multi-accelerants on the shelf-life of a shelf-stable product by investigating the extent of vitamins degradation and modeling the reaction using a mechanistic approach. A shelf-stable model food fortified with vitamins A, B1, C and D3 was developed to investigate the effect of multiple accelerants on the quality indicators of shelf-stable foods in a polyethylene terephthalate (PET) container. PET bottles filled with model food were placed in a high-pressure (138 kPa) 100% oxygen environment at 40 °C. This novel process is named as the ultra-accelerated shelf-life test (UASLT). Samples were also subjected to ASLT conditions at 40 °C and control condition at 22.5 °C, both at ambient pressure for comparison. UASLT treatment induced a rapid degradation of 27.1 ± 1.9%, 35.8 ± 1.0%, and 35.4 ± 0.7% in vitamins A, C and D3, respectively, in just 50 days. Slower degradation was observed with samples kept under the ASLT conditions for 105 days with a degradation of 24.0 ± 2.0%, 32.0 ± 3.1% and 25.1 ± 1.5% for vitamin A, C and D3, respectively. The control samples that were studied for 210 days showed 14.9 ± 5.0%, 13.8 ± 2.2% and 10.6 ± 0.8% degradation in vitamins A, C and D3, respectively. The increase in the ΔE values due to browning in samples kept at the UASLT, ASLT and control conditions were 11.67 ± 0.09, 7.49 ± 0.19 and 2.51 ± 0.11, respectively. The degradation of vitamin B1 was similar across the treatments. The addition of oxygen pressure significantly increased the degradation reaction rates of the vitamins and color due to the rapid influx of oxygen. A mechanistic model that coupled oxygen diffusion and simultaneous vitamin degradation provided a good fit to the experimental data for the UASLT treatment with a rate constant of 0.686, 0.631 and 0.422 M-1day-1 for vitamins C, D3 and A, respectively. Elevated external oxygen pressure can be used as an accelerant along with moderate temperatures for rapid shelf-life testing of products in polymeric packaging with two-fold reduction in the overall analysis time as compared to ASLT.

Preserving Ready-to-Eat Meals Using Microwave Technologies for Future Space Programs

The crewed suborbital and space flights launched by private companies over the past three years have rejuvenated public interest in space travel, including space tourism. Ready-to-eat meals (MREs) are the main source of nutrients and energy for space travelers. It is critical that those meals are free of bacterial and viral pathogens and have adequate shelf life. The participation of private companies in space programs will create new opportunities and demand for high-quality and microbiologically safe MREs for future space travels. In this article, we provide a brief review of nutrition and energy requirements for human activities in space. We discuss the general thermal processing requirements for control of bacterial and viral pathogens in MREs and introduce advanced thermal preservation technologies based on microwaves for production of MREs with different shelf-lives under various storage conditions. We also present the latest advancements in the development of polymer packaging materials for quality preservation of thermally stabilized MREs over extended storage. Finally, we recommend future research on issues related to the sensory quality of specially formulated MREs, microbial safety of dried foods that complement high moisture MREs, and food package waste management in future space missions.

Effect of Alternative Preservation Steps and Storage on Vitamin C Stability in Fruit and Vegetable Products: Critical Review and Kinetic Modelling Approaches

Vitamin C, a water-soluble compound, is a natural antioxidant in many plant-based products, possessing important nutritional benefits for human health. During fruit and vegetable processing, this bioactive compound is prone to various modes of degradation, with temperature and oxygen being recognised as the main factors responsible for this nutritional loss. Consequently, Vitamin C is frequently used as an index of the overall quality deterioration of such products during processing and post-processing storage and handling. Traditional preservation methods, such as thermal processing, drying and freezing, are often linked to a substantial Vitamin C loss. As an alternative, novel techniques or a combination of various preservation steps ("hurdles") have been extensively investigated in the recent literature aiming at maximising Vitamin C retention throughout the whole product lifecycle, from farm to fork. In such an integrated approach, it is important to separately study the effect of each preservation step and mathematically describe the impact of the prevailing factors on Vitamin C stability, so as to be able to optimise the processing/storage phase. In this context, alternative mathematical approaches have been applied, including more sophisticated ones that incorporate parameter uncertainties, with the ultimate goal of providing more realistic predictions.

Microwave applications in the food industry: an overview of recent developments

Microwave radiation has the ability to heat a material with dielectric properties. Material absorbs microwave energy and then converts it into heat, which gives the possibility of a wide use of microwaves in many industry sectors or agricultural sciences. Microwaves are especially widely used in food industry. The main objective of this paper is to present an overview of recent development regarding microwave applications in food industry. Many techniques in food processing (pasteurization, sterilization, drying, thawing, blanching and stunning) are assisted by microwave energy. It should be mentioned also the use of microwaves in nutrients and nutraceuticals production. Waste generation is an integral part of food production. Microwaves have also application in wastes management. The results of experiments, factors affecting heating and their practical application have been discussed. Many cases have been compared with conventional process methods. The use of microwaves shows many advantages. The most important aspect is shortening the time of the thermal process (even by 50%) and reducing the costs of the operation. In addition, it allows to increase the efficiency of processes while maintaining high quality. The examples of microwave applications given in the article are environmentally- friendly because the conditions of thermal processing allow for reducing the use of solvents and the amount of sewage by decreasing the demand for water. It is anticipated that microwaves will become increasingly popular, with the development of new microwave technologies solving many problems in the future.