Subcritical low temperature extraction of bioactive ingredients from foods and food by-products and its applications in the agro-food industry.

Bioactive ingredients are part of the food chain and are responsible for numerous health benefits. Subcritical low temperature extraction has been employed to acquire bioactive ingredients because of its excellent properties, such as energy conservation, low temperature, elimination of residual solvent, and high extraction yield and quality. This review aims to provide a clear picture of the basics of subcritical-temperature extraction, its bioactive ingredient extraction efficiency, and possible applications in the agro-food industry. This review suggested that the extraction temperature, time, co-solvents, solid-fluid ratio, and pressure impacted the extraction efficiency of bioactive ingredients from foods and food by-products. Subcritical solvents are appropriate for extracting low polar ingredients, while the inclusion of co-solvents could extract medium and high polar substances. Bioactive ingredients from foods and food by-products can be used as antioxidants, colorants, and nutritional supplements. Additionally, this technology could remove pesticide residues in tea, concentrate edible proteins, and reduce cigarette tar. A new trend toward using subcritical low temperature extraction in extracting bioactive ingredients will acquire momentum.

Novel intelligent films containing anthocyanin and phycocyanin for nondestructively tracing fish spoilage.

Potential pH-responsive films were developed based on incorporating anthocyanin, phycocyanin, and a mixture of anthocyanin-phycocyanin (at a ratio of 3:1 v/v) within composite gelatin (1.5 g / 100 g film solution)/soybean polysaccharide (2.5 g / 100 g film solution) matrices. FTIR and SEM assessments certified the incorporation of the pigments into the film matrices. All the colorimetric films were highly sensitive when exposed to headspace ammonia, except the phycocyanin-incorporated film. Moreover, the fabricated intelligent films were conducted to trace the spoilage process of grass carp. An obvious relationship between the color (L*, a*, b*, ΔE) of indicators and pH, TVB-N, bacterial growth, ATP-related compounds, and K-value of the fish was observed. The film incorporated with mixed Ipomoea nil extract and phycocyanin possessed the best color variations (dark orange, pink, dark blue) with the degree of fish spoilage. Therefore, this intelligent film can be considered a promising sensor for monitoring fish freshness non-destructively.

Improving the Gel Quality of Threadfin Bream (Nemipterus spp.) Surimi Using Salted Duck Egg White Powder.

The effect of salted duck egg white powder (SDEWP) as a source of salt at different salt equivalent (SE) levels (0−2.5% SE) on gel qualities and texture properties of threadfin bream surimi was investigated. SDEWP possessed a high protein (64.59%) and salt (34.86%) concentration. The breaking force of surimi gel increased by the amount of SDEWP (p < 0.05). The addition of SDEWP up to 1.5% SE into the surimi gel has significantly increased the deformation (13.8%) and decreased the expressible moisture content (38.5%). Hardness, gumminess, and chewiness were augmented as higher levels of SDEWP were added, whereas cohesiveness decreased when the SDEWP above 1.5% SE was used. The incorporation of SDEWP had no significant effect on the springiness (p < 0.05). Less proteolytic degradation was observed in the surimi gel fortified with SDEWP. A higher amount of added SDEWP enhanced the whiteness of the surimi gel (p < 0.05). A denser and more ordered gel network was attained when SDEWP with 1.5% SE was added. SDEWP could be exploited as a source for salt and non-fish proteins in threadfin bream surimi, in which SDEWP containing 1.5% SE could significantly improve the quality of surimi gel.

Recent advances in the application of microalgae and its derivatives for preservation, quality improvement, and shelf-life extension of seafood.

Seafood is a highly perishable food product due to microbiological, chemical, and enzymatic reactions, which are the principal causes of their rapid quality deterioration. Therefore, ever-increasing consumers' demand for high-quality seafood along with a negative perception of synthetic preservatives creates opportunities for natural preservatives such as microalgae extracts. They are potential alternatives to reduce microbial growth, increase oxidative stability, and protect the sensorial properties of seafood. Research has shown that the inclusion of microalgae extracts into the aquatic animal's diet could enhance their meat quality and increase production. This review focuses on the direct application of various microalgae extracts as seafood preservative, and their functional properties in seafood, such as antioxidant and antimicrobial activities. Besides, the potential nutritional application of microalgae extracts as an alternative in aqua-feed and their impact on seafood quality (indirect application) are also presented. The safety aspects and regulatory issues of products from microalgae are highlighted.

Insights into upstream processing of microalgae: A review.

The aim of this review is to provide insights into the upstream processing of microalgae, and to highlight the advantages of each step. This review discusses the most important steps of the upstream processing in microalgae research such as cultivation modes, photobioreactors design, preparation of culture medium, control of environmental factors, supply of microalgae seeds and monitoring of microalgal growth. An extensive list of bioreactors and their working volumes used, elemental composition of some well-known formulated cultivation media, different types of wastewater used for microalgal cultivation and environmental variables studied in microalgae research has been compiled in this review from the vast literature. This review also highlights existing challenges and knowledge gaps in upstream processing of microalgae and future research needs are suggested.

The effects of fatty acids chain length on the techno-functional properties of basil seed gum-based edible films.

In this study, the effects of various fatty (including caprylic, lauric, and palmitic) acids on physicochemical, mechanical, and barrier properties of basil seed gum (BSG)-based edible films were investigated. The introduction of fatty acids (FAs) into the BSG-based matrix was confirmed by FT-IR. Increasing the FA chain length resulted in an increase in the thickness and opacity of FA-modified BSG films, while water solubility decreased. The water vapor permeability (WVP) of FA-modified films was significantly (P < 0.05) lower than that of control film. The mechanical properties and color attributes of edible films were improved after incorporating caprylic and lauric acids. SEM micrographs revealed a more homogenous microstructure with a higher surface density in the films incorporated with caprylic acid, while a higher roughness and insoluble particles were observed in those incorporated with lauric, and palmitic acids. Our findings showed that lauric acid is a good candidate for improving the barrier and textural characteristics of BSG-based edible films.

Shelf-life enhancement of whole rainbow trout (Oncorhynchus mykiss) treated with Reshgak ice coverage.

The effect of ice coverage comprised of Reshgak extract and Reshgak essential oil on shelf-life extension of chilled whole rainbow trout (Oncorhynchus mykiss) was evaluated. Chemical (peroxide value (PV), thiobarbituric acids (TBA), total volatile nitrogen base (TVB-N), and free fatty acids (FFA)), microbiological (total viable count (TVC) and psychrotrophic viable count (PVC)), and sensory evaluations (texture, color, flavor, and general acceptance) were investigated every 4 days during a 20-day storage period. Results revealed that the effect of both icing systems led to considerably lower bacterial counts and chemical indices in comparison with the traditional ice coverage without such phytogenic. According to sensory analyses, fish stored in ice containing Reshgak essential oil had a longer shelf-life (>16 days) and those stored in ice medium included with Reshgak extract possessed a shelf-life of 16 days, whereas lot stored in traditional ice showed a shorter shelf-life of 12 days.