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The drying of insects is an important step in their processing. This research aimed to investigate the impact of a pulsed electric field (PEF), immersion in ethanol (EtOH), and combined (immersion in EtOH followed by PEF) treatment on the convective drying process, the emission of CO2, and the quality of the dried insects with regard to such elements as water content and activity, rehydration and hygroscopic properties, optical properties, internal structure, and microbiological quality. In applying a PEF, the drying time was made longer (up to 21%), but the rehydration and hygroscopic properties were improved (about 15–16.5% and 8.3–21.7%, respectively) compared to the untreated sample. Using a PEF prior to EtOH treatment improved the rehydration properties (about 3.9–5.9%), while the hygroscopicity was slightly lower compared to the PEF-treated samples. Furthermore, immersion in ethanol (both alone and after PEF) provided a lighter color of dried insects and more outstanding microbiological quality, e.g., the absence of water-borne and food-borne pathogens and anaerobic spore-forming bacteria. This study revealed that combined pretreatment seems to be the most promising method for insects as regards obtaining better rehydration and comparable hygroscopic properties, as well as an attractive color compared to untreated insects, and, above all, in ensuring suitable microbiological quality. [ABSTRACT FROM AUTHOR]

Edible insects may solve the current problem of the greater demand for food for the world's growing human population. This work aimed to examine the impact of blanching (BL) and ultrasound (US) at 20 and 50 °C as a pretreatment method on the chemical composition, mineral composition, FTIR spectra, presence of allergens and microorganisms, and properties of the isolated oil of freeze-dried superworm larvae. The US treatment resulted in significantly lower protein content (31.65–33.34 g/100 g d.m.) compared to untreated (36.38 g/100 g d.m.) and BL (37.72 g/100 g d.m.) samples. The study demonstrated that the US-treated insects exhibited a lower content of crustacean and mollusk allergens than the BL insects, and the lowest content of tested allergens was found in the US_50°C superworm larvae. Furthermore, oil isolated from US_50°C insects exhibited the lowest SFA and the highest PUFA content and the best prospective nutritional properties expressed through theoretical health indices. The presence of Enterobacteriaceae and anaerobic spore-forming bacteria was not detected in the tested insects, proving suitable microbiological quality. It appears that using US treatment is a promising alternative to traditional blanching of insects before drying. [ABSTRACT FROM AUTHOR]

This study emphasizes the significance of optimizing salt content during the fermentation of red beetroot to produce healthier and high-quality fermented products. It investigates the impact of different salt levels on fermentation, analyzing various parameters such as pH levels, dry matter content, total acidity, salt content, color changes, pigment content, and lactic acid bacteria count. This study identifies the most favorable salt concentration for bacterial growth during fermentation and storage as 2–3%. It was evaluated that salt levels fluctuated significantly during fermentation, with nearly 50% of the added salt absorbed by the beetroot tissues, mainly when lower salt concentrations were used. The fermentation process had a negative effect on the content of betalain pigments, as well as yellow pigments, including vulgaxanthin-I. It was also found that fermentation and storage affected the proportions of red pigments, with betacyanins proving to be more stable than betaxanthins, and that salt addition affected negatively pH and total acidity while causing an increase in yellow color. The pH was negatively correlated with the duration of the process, the amount of red pigment, and bacterial count. The results indicate that lower salt levels can lead to favorable physicochemical and microbiological parameters, allowing for the production of fermented red beetroot with reduced salt content without compromising quality. [ABSTRACT FROM AUTHOR]

Pumpkin is a highly nutritious plant, rich in valuable nutrients that benefit human health. Due to the high perishability of this fruit, the production of pumpkin juice is a practical way to use it effectively. Recently, fermented vegetable juices have been used as a dairy alternative due to their nutritional and potential probiotic properties. This study investigated the fermentation of pumpkin juice using different strains of lactic acid bacteria (LAB), with and without heat treatment. The effects of fermentation on microbial growth, pH, acidity, extract, sugars, carotenoids, polyphenols, and antioxidant properties were analyzed. The heat-treatment process did not greatly impact the dry matter content, pH, acidity, extract, or sugar content. However, it led to a reduction in carotenoid and polyphenol levels. During fermentation, there was a consistent decrease in pH and an increase in total acidity, with no noticeable differences between bacterial strains regarding their influence on these parameters. The study revealed that there were no distinctions between LAB strains in their effects on pH, acidity, and carotenoid content in fermented pumpkin juice. Nonetheless, both L. sakei and L. plantarum proved to be effective in the fermentation process, with L. sakei demonstrating greater adaptability. The expected pH, acidity, and sugar content changes were consistently observed throughout the fermentation process. Overall, results confirm the efficacy of the used Lactobacillus strains in fermenting pumpkin juice and highlight the potential impact of heat treatment on the nutritional composition of the juice. The purpose of thermal processing of pumpkin juice, which is conducted with lactic acid fermentation, is crucial for the food industry. It extends the product's shelf life, improves its nutritional and taste profiles, and guarantees its microbiological safety. [ABSTRACT FROM AUTHOR]

Cellular biomass of microorganisms can be effectively used in the treatment of waste from various branches of the agro-food industry. Urbanization processes and economic development, which have been intensifying in recent decades, lead to the degradation of the natural environment. In the first half of the 20th century, problems related to waste management were not as serious and challenging as they are today. The present situation forces the use of modern technologies and the creation of innovative solutions for environmental protection. Waste of industrial origin are difficult to recycle and require a high financial outlay, while the organic waste of animal and plant origins, such as potato wastewater, whey, lignin, and cellulose, is dominant. In this article, we describe the possibilities of using microorganisms for the utilization of various waste products. A solution to reduce the costs of waste disposal is the use of yeast biomass. Management of waste products using yeast biomass has made it possible to generate new metabolites, such as β-glucans, vitamins, carotenoids, and enzymes, which have a wide range of industrial applications. Exploration and discovery of new areas of applications of yeast, fungal, and bacteria cells can lead to an increase in their effective use in many fields of biotechnology.

The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil. [ABSTRACT FROM AUTHOR]

Featured Application: Single-cell protein is a type of protein derived from fungi and it has gained attention as a meat substitute due to its high protein content, low fat content, and specific texture. However, this type of protein can be used in the development of functional foods as well as additive to high-protein products, protein bars, shakes, snacks, dairy alternatives, etc. In recent years, there has been an increasing demand for new sources of protein, both for human and animal nutrition. In addition to alternative sources of protein, such as algae or edible insects, protein obtained from yeast and mold biomass is becoming more and more important. The main fungal protein producers are the yeasts Saccharomyces cerevisiae, Kluyveromyces marxianus, Candida utilis, Yarrowia lipolytica, and the molds Fusarium venenatum, Aspergillus oryzae, and Monascus purpureus. The production of fungal protein has many advantages, including the ability to regulate the amino acid composition, high protein content in dry matter, the possibility of production in a continuous process, independence from climatic factors, and the possibility of using waste substrates as ingredients of media. One of the disadvantages is the high content of nucleic acids, which generates the need for additional purification procedures before use in food. However, a number of enzymatic, chemical, and physical methods have been developed to reduce the content of these compounds. The paper presents the current state of knowledge about fungal producers, production and purification methods, the global market, as well as opportunities and challenges for single-cell protein (SCP) production. [ABSTRACT FROM AUTHOR]

The article aims to compare the properties and quality of two types of organic Japanese soy sauce from the market, declared by manufacturers as koikuchi, and tamari, both conventional and organic, along with an attempt to determine the differentiating factors using modern statistical methods. The amino acid profile showed the highest proportions were glutamic acid and aspartic acid. Tamari sauces could be distinguished from koikuchi by an elevated content of glutamic acid and alanine, while conventional and organic products differed the most in the shares of arginine, aspartic acid, and serine. The total polyphenol content was higher in conventional soy sauces and better antioxidant properties were found in koikuchi. Organic tamari sauces were characterized by higher antioxidant capacities and total flavonoid content. The volatile profile showed a significant difference between organic and conventional sauces. The research did not confirm that the quality of sauces declared as organic was significantly enhanced, and the overall quality of all tested sauces was high, both in terms of microbiological safety and physicochemical parameters. [ABSTRACT FROM AUTHOR]

Featured Application: A widely used method of food preservation is drying. Unfortunately, apart from the increase in the durability of the raw material and the decrease in its weight and volume, there are also negative changes related to its physical, chemical, and sensory properties. To reduce some unfavorable effects of the drying process, pretreatment can be used. Ultrasonic waves applied before drying in most cases positively affect the changes in food, obtaining high-quality products with changed physical properties. Additionally, ultrasounds have a positive impact on the efficiency of the technological process based on heat and mass transfer, reducing its duration, which results in lower production costs. Therefore, pretreatment using ultrasound is a promising alternative to the thermal pretreatment of raw materials. Beetroots are sources of bioactive compounds and valued pigments such as betalains. The purpose of this study was to determine the influence of ultrasound pretreatment on the beetroot infrared–hot air drying process and the functional properties of the obtained product. In this study, there were two used frequencies—21 and 35 kHz—and three different periods of time—10, 20, and 30 min. Since beetroots are usually subjected to thermal treatment, another aim was to examine the influence of blanching and soaking on the beetroot tissue properties in order to compare traditional and ultrasound-treated methods. As a result of this study, it was found that ultrasound pretreatment changed the dry matter content, water activity, thickness of the tissue, total color difference, and contents of betanin pigments in the beetroot. It was revealed that the drying process is shorter after ultrasound pretreatment using a 21 kHz frequency. Drying tissue exposed to ultrasounds showed a significant increase in the L* parameter; however, the decrease in the a* parameter was caused by a reduced content of betalain pigments. Taking into consideration parameters important from a technological point of view, it was found that the best condition for beetroot pretreatment is 20 min treatment, regardless of the frequency used. [ABSTRACT FROM AUTHOR]

Introduction: Due to its low cost and easy availability on the market, the petitgrain oil is commonly used in food, cosmetics, and aromatherapy. Objective: The examination of chemical composition and antibacterial activity of commercial petitgrain oil. Methods: Identification of chemical components of the petitgrain oil was performed by gas chromatography (GC). The minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) were determined using macrodilution method for the reference strains of bacteria and fungi. Results: Twenty components were identified. The petitgrain oil contained mostly oxygenated monoterpene hydrocarbons (98.01%), and the main components included linalyl acetate (48.06%) and linalool (26.88%). The MIC/MBC of the petitgrain oil for bacteria was in the range of 0.63-5.0/1.25-5.0 mg/ml and for fungi in the range of 1.25-40/5.0-80 mg/ml. Conclusion: The petitgrain oil had higher antibacterial activity than antifungal activity. Bacillus subtilis among the tested bacteria and Aspergillus niger and Penicillium expansum among the fungi were found to be highly inhibited by the petitgrain oil.

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