Emerging techniques applied to by-products for food fortification

Production of Acid and Rennet-Coagulated Cheese Enriched by Olive (Olea europaea L.) Leaf Extract-Determining the Optimal Point of Supplementation and Its Effects on Curd Characteristics

This study investigated the potential of olive leaf extract (OLE), as a functional ingredient, to improve cheese properties, because it is rich in phenols. Milk and dairy products are poor in phenolic compounds. The main objective was to determine the most effective coagulation method and timing of OLE supplementation to maximize retention in the cheese matrix. Experimental cheeses were produced using the rennet and acid coagulation methods, with OLE added either directly to the cheese milk or to the curd phase. Three OLE effective concentrations corresponding to 25%, 50%, and 75% inhibition of DPPH reagent (EFC25, EFC50, and EFC75, respectively) were added, i.e., 11.5 mg GAE L-1, 16.6 mg GAE L-1, and 26.3 mg GAE L-1, respectively. The results showed that OLE significantly increased the concentration of total phenols, total flavonoids, and antioxidant activity in all cheese samples and in the residual whey, especially at higher effective concentrations (EFC 50 and EFC 75). Rennet-coagulated cheese to which OLE was added prior to coagulation (EM 25, EM 50, EM 75) exhibited higher hardness, gumminess, and chewiness but lower elasticity, suggesting alterations in the paracasein matrix. OLE did not adversely affect acidity, water activity, or cheese yield. However, higher EFC resulted in significant colour changes (∆E* > 3.0). In conclusion, the enrichment of cheesemaking milk with OLE and the application of the rennet coagulation method are the most suitable to optimise the production of OLE-enriched cheese. This research shows the potential to improve the nutritional value of cheese while maintaining its desired characteristics.

Food-grade encapsulated polyphenols: recent advances as novel additives in foodstuffs

A growing inclination among consumers toward the consumption of natural products has propelled the usage of natural compounds as novel additives. Polyphenols are among the most popular candidates of natural food additives with multiple functionalities and bioactivities but are limited by instability. In this regard, a series of food-grade encapsulated polyphenols has been tailored for incorporating into food formulations as novel additives, which could better satisfy the complicated industry processing. This review seeks to present the most recent discussions regarding their application status in diverse foodstuffs as novel additives, involving functionalities, action mechanisms, and relevant encapsulation technologies. The scientific findings confirm that such novel additives show positive effects on physicochemical, sensory, and nutritional properties as well as the shelf life of diverse food matrices. However, poor heat resistance is still the major defect that restricts their application in thermal processes. Future research should focus on the evaluation of the compatibility and applicability of encapsulated polyphenols in real food processes as well as track and deepen their molecular action mechanisms in the context of complex foodstuffs. Innovation of existing encapsulation technologies should also be concerned in the future to bridge the gap between lab and scale-up production.

Development of Dairy Products Fortified with Plant Extracts: Antioxidant and Phenolic Content Characterization

In recent decades, there has been growing interest in the fortification of dairy products with antioxidants and phenolics derived from plant byproducts and herbs. The present study focused on the analysis of dairy products, including kefir, cream cheese, yogurt, and vegan yogurt, enhanced with aqueous extracts of plant byproducts (Citrus aurantium peel, Citrus limon peel and Rosa canina seed) and herbs (Sideritis spp., Hypericum perforatum, Origanum dictamnus, Mentha pulegium L., Melissa oficinallis, Mentha spicata L. and Lavandula angustifolia) to characterize their antioxidant content, phenolic profile, and organoleptic characteristics. Antioxidant and phenolic content were determined by Folin-Ciocalteu and ferric reducing antioxidant power (FRAP) assays and presented values up to 46.61 ± 7.22 mmol Fe²⁺/L and 82.97 ± 4.29 mg gallic acid (GAE)/g, respectively for the aqueous extracts, as well as up to 0.68 ± 0.06 mmol Fe²⁺/L and 2.82 ± 0.36 mg GAE/g for the fortified dairy products. The bioavailability of antioxidants and phenolics in fortified foods was determined after in vitro digestion and ranged between 4 and 68%. The phytochemical profile of the aqueous extracts was determined by mass spectrometry, and 162 phytochemicals were determined, from which 128 belong to the polyphenol family including flavonoids and phenolic acids. Furthermore, most of the identified compounds have been recorded to possess enhanced antioxidant capacity in correlation to the in vitro findings. Finally, organoleptic evaluation showed an overall acceptability around 3.0 ± 1.0 on a 5-point scale. In conclusion, the studied plants and herbal extracts can be used for the fortification of a variety of dairy products with potential positive effects on human health.

Genus Brassica By-Products Revalorization with Green Technologies to Fortify Innovative Foods: A Scoping Review

Food losses and waste reduction are a worldwide challenge involving governments, researchers, and food industries. Therefore, by-product revalorization and the use of key extracted biocompounds to fortify innovative foods seems an interesting challenge to afford. The aim of this review is to evaluate and elucidate the scientific evidence on the use of green technologies to extract bioactive compounds from Brassica by-products with potential application in developing new foods. Scopus was used to search for indexed studies in JCR-ISI journals, while books, reviews, and non-indexed JCR journals were excluded. Broccoli, kale, cauliflower, cabbage, mustard, and radish, among others, have been deeply reviewed. Ultrasound and microwave-assisted extraction have been mostly used, but there are relevant studies using enzymes, supercritical fluids, ultrafiltration, or pressurized liquids that report a great extraction effectiveness and efficiency. However, predictive models must be developed to optimize the extraction procedures. Extracted biocompounds can be used, free or encapsulated, to develop, reformulate, and/or fortify new foods as a good tool to enhance healthiness while preserving their quality (nutritional, functional, and sensory) and safety. In the age of recycling and energy saving, more studies must evaluate the efficiency of the processes, the cost, and the environmental impact leading to the production of new foods and the sustainable extraction of phytochemicals.