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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. [ABSTRACT FROM AUTHOR]

BACKGROUND: Epigallocatechin‐3‐gallate (EGCG) is well known for excellent chain‐breaking antioxidant capability. However, browning by oxidation and aggregation of EGCG is a non‐negligible defect that hinders its applications as an antioxidant in various foodstuffs. Therefore, how to eliminate or mitigate browning efficiently, while retaining functionalities as food additive is a challenge in the food industry. RESULTS: Our results demonstrated that EGCG could be anchored within the internal cavity of γ‐cyclodextrin (γ‐CD) to form an inclusion structure, where hydrophobic interaction, hydrogen bonding, and π‐stacking were identified to be the primary drivers. The interplay between two molecules and the steric hindrance from γ‐CD could restrict the motion and aggregation of EGCG efficiently, thus alleviating the browning effect. In addition, the conformational adaption of EGCG within the inclusions would result in general decreases in hydrogen‐bond dissociation enthalpies for the pyrogallol‐type structure on the b ring, thus enhancing the antioxidant capability. In practical application, the nanoscale γ‐CD/EGCG inclusion complexes were validated preliminarily as efficient additives in the preservation of shrimp surimi, presenting significant effects on prolonging the shelf‐life of products. CONCLUSION: Here, nanoscale γ‐CD/EGCG inclusion complexes as alternatives to EGCG were tailored as food antioxidants for the preservation of shrimp surimi products, exerting antioxidant effects while mitigating the browning effects of EGCG on products. Through self‐assembly, EGCG would be anchored with the cavity of γ‐CD, which could regulate the release modes and restrict the aggregation of EGCG. This facile strategy has great potential in food preservation. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Protein gelation is an important functional characteristic of shrimp surimi products. The effects of structurally relevant natural phenolic compounds on the structure and functional properties of myofibrillar protein (MP) of the Penaeus vannamei were investigated. In the present study, phenolics improved the oxidative stability of MP, while leading to a decrease in the emulsification properties of MP. The carbonyl and free radical contents and fluorescence quantification of protein oxidation products showed that the addition of phenolic compounds could effectively prevent MP oxidation due to their antioxidant capacity derived from hydroxyl groups. In addition, phenolics could improve the rheological properties and gelling behavior of MP. Finally, the interactions between the substituents of MP and phenolic compounds were explored by molecular docking to elucidate the modification mechanism. Gallic acid (GA), quercetin (QT), and (−)-epigallocatechin-3-gallate (EGCG) interacted with MP mainly through hydrogen bonding to unfold the secondary structure of MP and reduce the surface hydrophobicity. Unlike GA and EGCG, QT interacted electrostatically with MP, maintaining the α-helical structure and leading to a slight increase in surface hydrophobicity. This study demonstrated the great potential of phenolic compounds as natural additives for the functional modification of shrimp surimi products. [Display omitted] • Structure of phenolic compounds affected their interaction with MP. • Hydrogen bond and electrostatic interactions were found in the interactions. • Phenolics affected the structure and functional properties of MP. • Effect of GA and EGCG on functional properties of MP differed from quercetin. [ABSTRACT FROM AUTHOR]

Longan peel, which is fruit by-product, is known for its antioxidant activities regarding the presence of phenolics. To minimize the use of synthetic antioxidants in food, natural antioxidants including phenolics from plant extracts have received much interest. This study screened combinatorial pretreatments between longan peel extract (LP) and food additives including vitamin E (E) and ascorbyl palmitate (AP) for application in refined tuna oil. Our results demonstrated synergistic effects of LP/E/AP pretreatment against lipid oxidation in the oil. Under Rancimat accelerated oxidation at 100 °C, the LP/E/AP combination exhibited a synergy by significantly increasing induction period in comparison to the blank control. Similarly, under accelerated storage at 50 °C, this combination significantly decreased peroxide value, conjugated dienes and thiobarbituric acid reactive substances. Gas chromatography analysis demonstrated that the LP/E/AP combination maintained the levels of polyunsaturated fatty acids, which was comparable with that of a synthetic antioxidant i.e. butylated hydroxytoluene (BHT). In addition, the combined pretreatment resulted in synergistic decrease of free radicals in the oil, which might contribute to the antioxidative effects. Collectively, our results have demonstrated the potential of LP used in combination with particular food additives to enhance protective effects against lipid oxidation. [Display omitted] • Combination of LP/E/AP significantly improved oxidative stability of tuna oil. • Combination of LP/E/AP significantly protected PUFAs from oxidation. • LP is a potential food additive against lipid oxidation in oils. [ABSTRACT FROM AUTHOR]

• A feasible use strategy for EGCG is introduced and verified into surimi products. • γ-CD/EGCG complex act as a texture modifier and water retainer in shrimp surimi. • XPS and molecular docking are used in the regulation mechanism investigation. • Encapsulated EGCG avoids excessive crosslinking of myofibrillar proteins. • An encapsulation prior to use of EGCG give a higher phenolic retention in products. Epigallocatechin-3-gallate (EGCG) exhibits excellent cross-linking effects of myofibrillar proteins, it is prone to self-aggregation, causing excessive cross-linking and moisture loss of gels, which limits its application as a food additive in surimi products. Here, through combination γ-cyclodextrin and EGCG into one inclusion complex, we achieved proper usage of EGCG in shrimp surimi products: elevating both water holding capability and texture properties (hardness, chewiness and resilience). Moreover, the mechanism behind excellent performance was elucidated: as texture modifiers, the complexes improved gel network integrity through intermolecular interactions and moderated disulfide bonds; and as water retainer agents, the complexes promoted transformation of nitrogen in proteins towards the form of protonated amino, facilitating the occurrence of hydration. Furthermore, the inclusion complexes brought a higher phenolic retention within products in contrast with direct addition of EGCG. This work may propose novel insights for the usage of polyphenols as additives in surimi-based products. [ABSTRACT FROM AUTHOR]

• The ASPH exhibited better antioxidant activity than other two hydrolysates. • The ASPH showed good foaming properties and inhibition of lipid peroxidation. • The ASPH exhibited protective effects against oxidative cytotoxicity. Three scallop protein hydrolysates (SPH) were obtained by enzymatic hydrolysis of scallop meal by Pepsin, Dispase and Alcalase, respectively. The antioxidant activities of the SPHs were characterized for their free radical scavenging activities through 1,1-diphenyl-2-picrylhydrazyl (DPPH)/hydroxyl/2,2′ azino-bis-3-(ethylbenzthiazoline-6-sulphonic acid) (ABTS) assays, showing at least 60% radicals scavenging activities in samples (10 mg/mL). Moreover, the Alcalase-hydrolyzed SPH (ASPH) was shown to have the highest free radical scavenging activity determined by Electron Spin Resonance (ESR), due to the high proportion of antioxidant amino acids (35.25%) and better solubility. In addition, the ASPH also exhibited promising inhibitory effects (30–40%) against lipid oxidation in emulsifying system and excellent emulsifying and foaming properties. In vitro , the ASPH exhibited protective effects (nearly 20%) against H 2 O 2 -induced cytotoxicity probably due to the inhibition of mitochondria-associated generation of reactive oxygen species (ROS). The ASPH may potentially serve as a high-valued scallop-based food additive with great health benefits. [ABSTRACT FROM AUTHOR]