Impact of high-pressure processing on microbial shelf-life and protein stability of refrigerated soymilk

Microbial Shelf-Life, Starch Physicochemical Properties, and in Vitro Digestibility of Pigeon Pea Milk Altered by High Pressure Processing

This study examined the effects of high-pressure processing (HPP) on microbial shelf-life, starch contents, and starch gelatinization characteristics of pigeon pea milk. HPP at 200 MPa/240 s, 400 MPa/210 s, and 600 MPa/150 s reduced the count of Escherichia coli O157:H7 in pigeon pea milk by more than 5 log CFU/mL. During the subsequent 21-day refrigerated storage period, the same level of microbial safety was achieved in both HPP-treated and high-temperature short-time (HTST)-pasteurized pigeon pea milk. Differential scanning calorimetry and scanning electron microscope revealed that HPP at 600 MPa and HTST caused a higher degree of gelatinization in pigeon pea milk, with enthalpy of gelatinization (∆H) being undetectable for both treatments. In contrast, HPP at 400 MPa led to an increase in the onset temperature, peak temperature, and conclusion temperature, and a decrease in ∆H, with gelatinization percentages only reaching 18.4%. Results of an in vitro digestibility experiment indicate that maximum resistant starch and slowly digestible starch contents as well as a decreased glycemic index were achieved with HPP at 400 MPa. These results demonstrate that HPP not only prolongs the shelf-life of pigeon pea milk but also alters the structural characteristics of starches and enhances the nutritional value.

Effect of carbon dots in combination with aqueous chitosan solution on shelf life and stability of soy milk

Use of carbon dots (CDs) in combination with aqueous chitosan solution to extend shelf life and improve stability of soy milk was investigated. Soy milk samples with chitosan solution (0.00%, 0.08%, 0.12%, 0.16% and 0.20%) and banana-based CDs (4%, 6% and 8%) were prepared and stored at room temperature (25-30 °C) for shelf life evaluation. Soy milk with 0.16% chitosan solution exhibited improved stability as evident by increased viscosity, stability coefficient, zeta potential and decreased centrifugation rate compared with soy milk without chitosan. The suitable amount of carbon dots could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Soy milk with 0.16% chitosan and 8% CDs exhibited longer shelf life and significantly lower total bacterial count after storage at room temperature for up to 4 days. Electronic nose-based flavor characteristics of all treated soy milk samples were not far from that of the control sample.

Effect of Innovative Food Processing Technologies on the Physicochemical and Nutritional Properties and Quality of Non-Dairy Plant-Based Beverages

Increase in allergenicity towards cow’s milk, lactose intolerance, the prevalence of hypercholesterolemia, and flexitarian choice of food consumption have increased the market for cow’s milk alternatives. Non-dairy plant-based beverages are useful alternatives because of the presence of bioactive components with health-promoting properties, which attract health-conscious consumers. However, the reduced nutritional value and sensory acceptability of the plant-based beverages (such as flavor, taste, and solubility) compared to cow’s milk pose a big threat to its place in the market. Thermal treatments are commonly used to ensure the quality of plant-based beverages during storage. However, the application of high temperatures can promote the degradation of thermolabile compounds and some detrimental reactions, thus reducing protein digestibility and amino acid availability of non-dairy plant-based beverages substitutes. New and advanced food processing technologies, such as high-pressure processing, high-pressure homogenization, pulsed electric fields, and ultrasound, are being researched for addressing the issues related to shelf life increase, emulsion stability, preservation of nutritional content and sensorial acceptability of the final product. However, the literature available on the application of non-thermal processing technologies on the physicochemical and nutritional properties of plant-based beverages is scarce. Concerted research efforts are required in the coming years in the functional plant-based beverages sector to prepare newer, tailor-made products which are palatable as well as nutritionally adequate.

Health issues and technological aspects of plant-based alternative milk

A growing number of consumers opt for plant-based milk substitutes for medical reasons, like cow's milk protein allergy (CMPA), lactose intolerance (LI), or as a lifestyle choice. Plant-based milk substitutes, or plant extracts, are water-soluble extracts of legumes, oilseeds, cereals or pseudocereals that resemble bovine milk in appearance. It is produced by reducing the size of the raw material, extracted in water and subsequently homogenized, being an alternative to cow's milk. They are considered cow's milk replacers due to similar chemical composition and can also be used as a substitute for direct use or in some animal milk-based preparations. On the other hand, these substitutes exhibit different sensory characteristics, stability and nutritional composition from cow's milk. They are manufactured by extracting the raw material in water, separating the liquid, and formulating the final product. Others process like homogenization and thermal treatments are indispensable to improve the suspension and microbiological stabilities of the final product so that can be consumed. However new and advanced non-thermal processing technologies such as ultra-high pressure homogenization and pulsed electric field processing are being researched for tackling the problems related to increase of shelf life, emulsion stability, nutritional completeness and sensory acceptability without the use of high temperatures. Some pre-treatments such as peeling, bleaching or soaking can be performed on the raw material in order to improve the final product. The nutritional properties are influenced by the plant source, processing, and fortification. The addition of other ingredients as sugar, oil and flavorings is done to the plant-based milk substitute to make them more palatable and be more acceptable to consumers. Thus, the aim is to review the main reasons for the consumption of plant-based milk substitute as well as the raw materials used and the technological aspects of its production.

Recent Advances in Physical Post-Harvest Treatments for Shelf-Life Extension of Cereal Crops

As a result of the rapidly growing global population and limited agricultural area, sufficient supply of cereals for food and animal feed has become increasingly challenging. Consequently, it is essential to reduce pre- and post-harvest crop losses. Extensive research, featuring several physical treatments, has been conducted to improve cereal post-harvest preservation, leading to increased food safety and sustainability. Various pests can lead to post-harvest losses and grain quality deterioration. Microbial spoilage due to filamentous fungi and bacteria is one of the main reasons for post-harvest crop losses and mycotoxins can induce additional consumer health hazards. In particular, physical treatments have gained popularity making chemical additives unnecessary. Therefore, this review focuses on recent advances in physical treatments with potential applications for microbial post-harvest decontamination of cereals. The treatments discussed in this article were evaluated for their ability to inhibit spoilage microorganisms and degrade mycotoxins without compromising the grain quality. All treatments evaluated in this review have the potential to inhibit grain spoilage microorganisms. However, each method has some drawbacks, making industrial application difficult. Even under optimal processing conditions, it is unlikely that cereals can be decontaminated of all naturally occurring spoilage organisms with a single treatment. Therefore, future research should aim for the development of a combination of treatments to harness their synergistic properties and avoid grain quality deterioration. For the degradation of mycotoxins the same conclusion can be drawn. In addition, future research must investigate the fate of degraded toxins, to assess the toxicity of their respective degradation products.