The extraction of bioactive compounds from food wastes or by‐products with natural deep eutectic solvents (NADES) could be an attractive alternative to traditional hydroalcoholic extraction but needs to be optimized taking advantage of modeling. This work aims to propose, develop, and discuss a new model for the extraction of phenolic compounds from spent coffee grounds (SCGs) using NADES to overcome some gaps related to the kinetic extraction models and the surface response methodology. The model presented is based on the same assumption as the kinetic model, but improving it to be able to predict phenolic extraction changing different process parameters (e.g., water content, time of extraction, temperature, etc.) using betaine: triethylene glycol (molar ratio 1:2). The model was validated on the extraction of total phenolic compounds from SCG as a function of water content of NADES ranging from 30 to 60% v/v. There was good agreement between experimental and simulated data and even, in some cases, better than with the second‐order kinetic models. In addition, the new model needs fewer parameters to be regressed concerning the specific case investigated in this work. This model and methodology can be the basis for further modeling applicable to other bioactives, and/or other NADES and feedstocks.Practical Applications: Natural deep eutectic solvents (NADES) can be a potential sustainable solvent for the valorization of food by‐products as they can be used to extract bioactive compounds with high added value. This extraction process needs to be optimized depending on several factors like water content in NADES solution, solids ratio, extraction time, and temperature. The model validated in this work on spent coffee ground (SCG) could be used for this purpose, improving the gaps related to the kinetic extraction models and the surface response methodology (RSM). The new model enables predicting the behavior of the process as a function of the parameters previously mentioned and reduces the number of experimental trials required compared with RSM. In particular, the new model was validated on the variation of water content in NADES solution. Certainly, this model will need to be further validated, but, once further studies are conducted, this model could be used for scale‐up calculation and design optimization of the industrial process.
Winemakers have to deal with enzymatic browning caused by a grape polyphenol oxidase called tyrosinase. Due to the problems related to sulphur dioxide and its use in winemaking, oenologists need alternative and effective treatments for inhibiting enzymatic browning. This research studies ascorbic acid, glutathione (pure and in the form of a specific inactivated dry yeast rich in glutathione), and bioprotection by a selected strain of Metschnikowia pulcherrima as alternatives to SO2 for preventing enzymatic browning, following a methodology developed in previous works. All the studied treatments resulted in a significant reduction in enzymatic browning. More specifically, all treatments significantly reduced the Vmax of the apparent tyrosinase activity, indicating their potential to protect against enzymatic browning and thus allowing for a reduction in the doses of SO2 added to the wine.