Enzyme Catalysis in Biochemistry

The amount of food waste is increasing with the development of society and the increase in population; the rough treatment of food waste could result in a serious environmental crisis and waste of resources. Hydrothermal treatment is a promising scheme to achieve the harmless treatment and utilization of food waste. Although there are many studies on the hydrothermal treatment of food waste, there is still a lack of systematic summary and comprehensive analysis of the relevant literature. In this review, we provide an in-depth analysis of the specific impact mechanisms of hydrothermal conditions on the gaseous, solid, and liquid products. Meanwhile, the hydrothermal conversion mechanisms of food waste components are systematically sorted out. The review also discusses the potential application areas for the derived products from the hydrothermal treatment of food waste. Finally, the main challenges and future research directions are proposed to improve the development of the hydrothermal treatment of food waste.

A key problem, which requires solution in today’s situation, is treatment of food waste. Nowadays food waste is mainly buried and it does harm to the environment and people’s heals, pollutes air because of dump gases (including greenhouse gases), soil and water and causes irreversible climatic changes. It is necessary to pass over to such level of production and consumption, which could minimize and even eliminate waste formation. The authors of the article substantiate the need to take steps aimed at waste involvement in economic turn-over by its recycling, which requires the development of the effective mechanism of food waste control in the Russian Federation. The economic mechanism shall include the system of normative, legal and other documents in the field of treating food waste, a set of technological and infrastructure decisions aimed at utilization of food products with expiring BB dates, methodological recommendations on cutting food waste formed in business activity and its utilization.

Immobilised enzymes as drugs

Recent progress in multienzymes co-immobilization and multienzyme system applications

Non-negligible health risks caused by inhalation exposure to aldehydes and ketones during food waste treatments in megacity Shanghai

Effect of carbon dioxide on thermal treatment of food waste as a sustainable disposal method

Lipase is a biocatalyst capable of catalyzing the hydrolysis or synthesis of triglycerides. It is widely distributed in animals, plants, and microorganisms. Owing to its high efficiency, specificity, and mild reaction conditions, lipase has demonstrated significant value in food processing, nutritional enhancement, and waste treatment. This paper reviews the sources of lipase and its applications in food processing, flavor improvement, and nutritional enhancement, as well as discusses its future development trends. Lipase can be utilized in oil modification, dairy product processing, baked goods, meat product processing, and other areas to enhance food quality and nutritional value. Furthermore, lipase exhibits substantial potential in the utilization of food waste resources and the development of functional foods. With advancements in enzyme engineering technology and deeper insights into the mechanism of lipase, its application in food biology will become increasingly extensive and profound.

Collocation on finite element (CFE) is an effective simultaneous method of dynamic optimization to increase the profitability or productivity of industrial process. The approach needs to select an optimal mesh of time interval to balance the computational cost with desired solution. A new CFE approach with non-uniform refinement procedure based on the sensitivity analysis for dynamic optimization problems is, therefore, proposed, where a subinterval is further refined if the obtained control parameters have significant effect on the performance index. To improve the efficiency, the sensitivities of state parameters with respect to control parameters are derived from the solution of the discretized dynamic system. The proposed method is illustrated by testing two classic dynamic optimization problems from chemical and biochemical engineering. The detailed comparisons among the proposed method, the CFE with uniform mesh, and other reported methods are also carried out. The research results reveal the effectiveness of the proposed approach.

Microwave irradiation and biocatalysis are important and rapidly developing technologies in green and sustainable engineering. The synergistic effect of microwave irradiation and lipase catalysis in transesterification of ethyl (2E)-3-phenylprop-2-enoate and 4,8-dimethylnon-7-en-1-ol was studied using immobilized enzymes such as Novozym 435, Lipase AYS amino, Lipozyme RMIM and Lipozyme TL IM. Novozym 435 was the best catalyst amongst studied. The effects of various parameters affecting the conversion and initial rates of transesterification were studied to establish kinetics and mechanism. There is synergism between enzyme catalysis and microwave irradiation, an increase in initial rates up to 2.3-fold was observed under microwave irradiation than that under conventional heating. With a substrate concentration of 0.03333 kmol/m3 of ethyl (2E)-3-phenylprop-2-enoate and 0.06667 kmol/m3 of 4,8-dimethylnon-7-en-1-ol in n-heptane, Novozym 435 offered a conversion of 94 % at 333 K in 21600 s. The analysis of initial rate data and progress curve data showed that the reaction obeys ternary complex ordered bi–bi mechanism with inhibition by 4,8-dimethylnon-7-en-1-ol. The theoretical predictions and experimental data match very well. These studies were also extended to other alcohols viz, n-butanol, n-pentanol, (3Z)-4,8-dimethylnon-3,7-dien-1-ol, benzyl alcohol, isoamyl alcohol, glycidol and 1,4-butanediol

Simple SummaryBlack soldier fly larvae (BSFL) have received global research interest and industrial application due to their high performance on the organic waste treatment. However, the substrate C/N property, which may affect larvae development and the waste bioconversion process greatly, is significantly less studied. The current study focused on the food waste treatment by BSFL, compared the nitrogen supplying effects of 9 nitrogen species (i.e., NH4Cl, NaNO3, urea, uric acid, Gly, L-Glu, L-Glu:L-Asp (1:1, w/w), soybean flour, and fish meal), and further examined the C/N effects on the larval development and bioconversion process. We found that NH4Cl and NaNO3 led to poor larval growth and survival, while 7 organic nitrogen species exerted no harm to the larvae. Urea was further chosen to adjust the C/Ns. Results showed that lowering the C/N from the initial 21:1 to 18:1–14:1 improved the waste reduction and larvae production performance, and C/N of 18:1–16:1 was further beneficial for the larval protein and lipid bioconversion, whereas C/N of 12:1–10:1 resulted in a significant performance decline. Therefore, the C/N range of 18:1–16:1 is likely the optimal condition for food waste treatment by BSFL and adjusting food waste C/N with urea could be a practical method for the performance improvement.Biowaste treatment by black soldier fly larvae (BSFL, Hermetia illucens) has received global research interest and growing industrial application. Larvae farming conditions, such as temperature, pH, and moisture, have been critically examined. However, the substrate carbon to nitrogen ratio (C/N), one of the key parameters that may affect larval survival and bioconversion efficiency, is significantly less studied. The current study aimed to compare the nitrogen supplying effects of 9 nitrogen species (i.e., NH4Cl, NaNO3, urea, uric acid, Gly, L-Glu, L-Glu:L-Asp (1:1, w/w), soybean flour, and fish meal) during food waste larval treatment, and further examine the C/N effects on the larval development and bioconversion process, using the C/N adjustment with urea from the initial 21:1 to 18:1, 16:1, 14:1, 12:1, and 10:1, respectively. The food wastes were supplied with the same amount of nitrogen element (1 g N/100 g dry wt) in the nitrogen source trial and different amount of urea in the C/N adjustment trial following larvae treatment. The results showed that NH4Cl and NaNO3 caused significant harmful impacts on the larval survival and bioconversion process, while the 7 organic nitrogen species resulted in no significant negative effect. Further adjustment of C/N with urea showed that the C/N range between 18:1 and 14:1 was optimal for a high waste reduction performance (73.5–84.8%, p < 0.001) and a high larvae yield (25.3–26.6%, p = 0.015), while the C/N range of 18:1 to 16:1 was further optimal for an efficient larval protein yield (10.1–11.1%, p = 0.003) and lipid yield (7.6–8.1%, p = 0.002). The adjustment of C/N influenced the activity of antioxidant enzymes, such as superoxide dismutase (SOD, p = 0.015), whereas exerted no obvious impact on the larval amino acid composition. Altogether, organic nitrogen is more suitable than NH4Cl and NaNO3 as the nitrogen amendment during larval food waste treatment, addition of small amounts of urea, targeting C/N of 18:1–14:1, would improve the waste reduction performance, and application of C/N at 18:1–16:1 would facilitate the larval protein and lipid bioconversion process.

Identifying key process parameters for uncertainty propagation in environmental life cycle assessment for sewage sludge and food waste treatment

Objectives : Black soldier fly larvae (BSFL) are organisms that effectively decompose various types of organic waste including food waste, and food waste treatment using BSFL is attracting attention as a sustainable waste treatment method. However, food waste discharged from Korea has a wide variety of properties, and its high salt concentration limits its treatment by BSFL. Therefore, to increase the efficiency of food waste treatment using BSFL, it is necessary to increase the quality of food waste as a production medium for BSFL. In this study, the ratio of protein and fat was adjusted by adding bean sprouts and wheat brans to food wastes treated at high temperature under vacuum, and whether such medium is suitable for rearing BSFL was investigated.Methods : To improve the medium, the ratio of protein and fat was adjusted to approximately 2:1 by adding bean sprouts and bran residue to food waste. Subsequently, the growth and development rate of BSFL reared on chicken feed, food waste, food waste + bean sprouts, food waste + wheat bran were measured. Also, the decomposition rate of each medium was analyzed.Results and Discussion : The growth rate of BSFL grown on food waste + wheat bran medium was similar to that of BSFL reared on chicken feed. The speed of development at day 7 was also the fastest for BSFL reared with food waste + wheat bran medium and chicken feed. These results suggest that the mixed medium to which wheat bran has been added to food waste has the potential to be used as a commercial medium for BSFL production. The survival rate of BSFL was 89% or higher in all media.Conclusions : When food waste was used alone, BSFL development was poor compared to that in media combined with agricultural by-products such as bean sprouts and wheat bran. Therefore, to use food waste as a rearing medium of BSFL, it is necessary to adjust the ratio of protein and fat by adding various agricultural by-products and reduce salinity. For the improvement of food waste treatment technology using BSFL, mass rearing of useful insects such as BSFL, and promotion of the use of agricultural by-products, additional research is needed to optimize the composition of rearing medium based on food waste.

Anaerobic digestion (AD) is an established method that has been extensively utilized for waste management, waste treatment, and biogas production. Anaerobic co-digestion (AcoD) is regarded as a practical approach to address substrate characteristics and system optimization issues. The distinction between AcoD and mono-digestion is that AcoD has a higher organic loading and significant substrate composition variation. There are many factors involved in AcoD which affect the biogas plant’s production ability and performance. Using response surface methodology (RSM) to forecast the optimal conditions for maximum biogas output, this article provides an overview of the different operational parameters in the AcoD process, modeling of the AcoD process, and overall process optimization. Standard software used for AcoD process simulation are Aspen Plus, SuperPro Designer, BioWin, CFD, and MATLAB. Review addresses design, development, and optimization frameworks for biogas production systems that take numerous aspects into account. The most significant AcoD optimization parameters include temperature, co-substrate concentration, inoculum ratio (percent), and C/N ratio.

1] Introductionk

Pilot-scale multi-purposes approach for volatile fatty acid production, hydrogen and methane from an automatic controlled anaerobic process