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Abstract: BACKGROUND: Preferential crystallization is a common technique used in the purification of enantiomers, proving that crystallization may also be applied to the purification of very similar molecules by seeding the solution with the desired compound. Nonetheless, its application to other organic molecules is less widely documented in the literature. Knowing that chemically related polyphenols are generally co‐produced by fermentation and their purification can be too expensive for their market value, this technique may contribute to developing a downstream process with less expensive steps. The goal of this work is to show the applicability of the preferential crystallization concept to the purification of similar polyphenols – naringenin and trans‐resveratrol – with either single or coupled crystallizers. RESULTS: After developing the required crystallization kinetic models, an experiment using two coupled vessels was devised, where a 63% yield of naringenin and 44% yield of trans‐resveratrol was obtained, with ≥98% purity in both cases. When the vessels were working independently, 81% of pure trans‐resveratrol (started 60% pure) and 70% of pure naringenin (started 68% pure) were recovered. CONCLUSION: The experiments performed show the possibility of separately purifying two similar molecules (from 60% to roughly 100%) with promising yields, despite their similar solubility. This method, which can be significantly improved, might provide an economically attractive way for the production of low added value products. © 2017 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Adsorption can be an effective way of purifying polyphenols from complex mixtures. However, polyphenols may be present in small concentrations, making it difficult to selectively adsorb them onto standard hydrophobic resins and obtain appreciable adsorption. In this work, nonfunctionalized hydrophobic resins (Amberlite XAD-7HP, XAD-16) are compared with functionalized resins with imidazole (Biotage RENSA PX) and pyridine (RENSA PY) in terms of capacity and selectivity toward p-coumaric acid, trans-resveratrol, and naringenin. The obtained results indicate that, due to hydrogen bonding, the functionalized resins provide more capacity (e.g., 80 mg·g–1 vs 11.3 mg·g–1 for trans-resveratrol) and up to five times more selectivity than standard resins. Despite such strong affinity, at low pH, the isotherm slope can decrease up to four times when compared to the XAD resins for the same ethanol content, making desorption easier. The included isotherm data is enough to model any chromatography dynamic simulation for the studied compounds. [ABSTRACT FROM AUTHOR]

Sinapic acid is a potential valuable compound to be recovered from rapeseed meal extracts as it processes antioxidant and antimicrobial properties. However, the concentration of this compound might be low and the presence of other low value compounds could complicate its downstream processing. Adsorption is an alternative technique that might allow selective recovery of this compound. This work was focused on establishing the foundation of an industrial process design to recover sinapic acid by adsorption. The obtained results from multicomponent experiments indicate that, resin Amberlite™ FPX66 is the best performing one showing a maximum adsorption capacity of 102.6 ± 11.7 mg/gresin, easy sinapic acid recovery by desorbing it with 70% ethanol and high selectivity to sinapic acid over glucose, phytic acid and glucosinolates. The obtained equilibrium information was applied as input in a dynamic column model and compared with experimental results, showing a good agreement (r2 = 0.98). The model can be further applied for a large-scale chromatography process design to recover sinapic acid from rapeseed/canola meal extracts. [ABSTRACT FROM AUTHOR]

Modified UNIFAC (Mod. UNIFAC) is a proven model for the prediction of activity coefficients of molecules in non-ideal mixtures. However, Mod. UNIFAC is often not accurate when hydrogen bonding or strong hydrophobic interactions are present. An interesting group of molecules called polyphenols presents both types of interactions and therefore, Mod. UNIFAC predictions are not always accurate. A polyphenol-specific UNIFAC-based method (MPP-UNIFAC) has been developed in this study for its application on polyphenol-like molecules. Interaction parameters were regressed from 410 solubility data points from polyphenols in literature showing a good fit. The average error of the fit is 0.094 log units, better than the average value for Mod. UNIFAC (0.5 log units). Moreover, the model was validated against three datasets that were not used for the regression giving more accurate predictions than the Mod. UNIFAC it was developed from. [ABSTRACT FROM AUTHOR]

This work focuses on the rapid selection of a resin from a defined set of macroporous polymeric resins for the decaffeination of catechins from green tea. High-throughput experimentation and design of experiments are used in order to retrieve as much information as possible from a small set of experiments on the interaction of components with the resins. A multicomponent Langmuir isotherm model is used to describe the adsorption and parameters are regressed with high accuracy. These parameters are subsequently used for the definition of criteria to calculate a weighted resin score. The optimal resin is Diaion 2OHP with a score of 90.50%, mainly due to its good selectivity for caffeine over catechin (3). [ABSTRACT FROM AUTHOR]

• Adsorption can be efficiently used in food industry. • Agri-food by-product rapeseed meal extract provides valuable components. • CaptureSMB designed for semi-continuous adsorption to purify polyphenols. • CaptureSMB outperforms batch operation performance regarding productivity and resin utilization. • Mathematical modeling allows fast and fair comparison of separation performance. Efficient recovery and utilization of valuable components from industrial food side streams is a main driver towards a circular economy. Among different available purification techniques, adsorption can effectively recover these components. However, the conventional batch mode of operation can limit its applicability in food processes due to limited efficiency. This work compares conventional batch packed bed adsorption with semi-continuous adsorption (so-called CaptureSMB) for the recovery of sinapic acid at industrial scale, using a food grade resin AmberliteTM FPX66. A mathematical mechanistic model able to describe semi-continuous operation is successfully validated and used to identify optimum operating parameters to maximize productivity and resin capacity utilization in batch and semi-continuous operating modes. The results indicate that CaptureSMB outperforms batch operation, increasing productivity from 5.18 g/L/h to 10.3 g/L/h for a given yield (>97%). A resin capacity utilization (RU) of around 70% is observed in both operating modes when productivity is maximized. A 92% RU can be accomplished for a given yield using the CaptureSMB process at a productivity of 7.0 g/L/h, higher than for conventional batch operation. The use of semi-continuous adsorption operation in food industry contributes to more efficient processes at reduced purification costs. [ABSTRACT FROM AUTHOR]