Color is a crucial sensory indicator of wine quality. However, changes in anthocyanin concentration and profile occur during wine aging, resulting in noticeable reductions in chroma and shifts in hue from purple to brick red. This is because monomeric anthocyanins degrade and derivative anthocyanins form. The rate of color changes can vary depending on complex factors, such as the anthocyanin content of the must, oenological technology, and environmental conditions, which makes the management of red wine color evolution challenging. To address this issue, appropriate winemaking techniques are required to achieve an elegant wine color. This review summarizes the mechanisms related to anthocyanin stability, including glycosylation, acetylation, and derivatization. The review also discusses factors influencing red wine color fading for specific grape varieties and wine appellations, offering time- and cost-efficient techniques to accelerate anthocyanin derivatization and color stabilization.

Not from concentrate (NFC) fruit juice is the crucial clean label ingredient for new-style tea-making due to its pleasant color and fresh aroma. Here, we compared the effects of mild heating (MH) and high pressure processing (HPP) on physicochemical characters and phytochemicals in NFC spine grape juice based on metabolomics analysis. Similar compound profiles were observed between HPP-treated and fresh juices. The richer phytochemical compounds comprised malvidin-3-O-glucoside, malvidin-3,5-di-O-glucoside, quercetin-3-O-rhamnoside, quercetin-3-O-glucuronide, catechin, caffeic acid, ferulic acid, procyanidin B1, procyanidin B2 were obtained after MH treatment. Nine marker phenolics and two marker tripeptides (i.e., Glu-Val-Phe and Leu-Leu-Tyr) were identified to differentiate MH from HPP treatment, of which higher contents occurred in the MH group. Storage time experiments showed that the Glu-Val-Phe could serve as potential markers for monitoring storage of spine grape juice. These results provide new insights into the effects of processing on individual phytochemical changes and the guide for commercial application of production of spine grape NFC juice.

The promising future of natural colors in the food industry aligns with the shift in consumer preference toward healthier food options. These naturally derived ingredients gradually replace their artificial counterparts and find applications in a wide range of food categories, and aquatic products have emerged as one of them. In this work, we introduced the characteristics and extraction of several main types of natural pigments and also explored the positive outcomes of integrating the pigments, such as carotenoids, curcumin, anthocyanins, and betalains, in aquatic product processing and preservation. Their outstanding antioxidant and dyeing properties contribute to the production and storage of various aquatic products. This review aims to provide a comprehensive understanding of the current state of natural pigment applications in aquatic products and to provide inspiration for future research and industry practices.