Polyphenol bioactivity evolution during the spontaneous fermentation of vegetal by-products.

Food industry by-products such as grape pomace (GP), tomato pomace (TP), and spent coffee grounds (SCG) are rich in polyphenols (PP) but are easily biodegradable. The aim of this study is to test Spontaneous Fermentation (SF) as treatment to modify PP profile and bioactivity. The results highlighted that the by-products' organic matter and the microbial populations drove the SF evolution; heterolactic, alcoholic, and their mixtures were the predominant metabolisms of TP, GP, and SCG + GP co-fermentation. Increases in the extractable amounts and antiradical activity occurred for all the biomasses. Regarding the aglycate-PPs (APP), i.e. the most bioreactive PPs, significant changes occurred for TP and GP but did not influence the anti-inflammatory bioactivity. The co-fermentation increased significantly chlorogenic acid and consumed most of the APPs, acting as a purification system to obtain a highly concentrated APP fraction, so that the extract might be employed for a specific purpose.

Antioxidant and Anti-Inflammatory Activities of the Crude Extracts of Raw and Fermented Tomato Pomace and Their Correlations with Aglycate-Polyphenols.

Two tomato pomace (TP) were studied as feedstocks to obtain extracts that are rich in polyphenols. TPs prompt degradation impairs biomass safety, thus naturally present microflora were tested to perform conservation, and own lactic bacteria became predominant after 60 days of treatment. The extracts of TPs and TPs fermented (TPF) were chemically characterized and tested for antioxidant and anti-inflammatory activities. Flavonoids and phenolic acids were classed as aglycone-polyphenols (A-PP), the most bioactive polyphenol fraction. Fermentation led to a reduction of the A-PP amount, but no significant change in composition. Antioxidant power increased, despite the A-PP reduction, for the presence of fermentation metabolites having aromatic-substituent. TP and TPF both have anti-inflammatory properties that were strictly dependent upon the A-PP content. Fermentation preserved the anti-inflammatory activity and the Partial Least Square (PLS) identified as the most active molecules naringenin chalcone, kaempferol, gallic acid, and cinnamic acid, together with the definition of the active dose.

Supercritical CO2 extraction of tomato pomace: Evaluation of the solubility of lycopene in tomato oil as limiting factor of the process performance.

This work considered lycopene (lyc) amount and (all-E)-lyc:Z-lyc (E:Z) ratio as driving parameters of the tomato pomace (TP) supercritical CO2 extraction (SFE_CO2) performance. By testing lyc concentrations solubilization in tomato seed oil and E:Z ratios of 75:25, 59:39 and 25:75, full and partial equations (SE) were calculated. The application of mass balances to experimental TP_SFE_CO2 highlighted an extraction yield of 84.6% TP lyc, although the recovery into the extract was 48.4% of the extracted lyc (lyc = 1339 µg g-1 oil). The SE application to TP_SFE_CO2 data confirmed that partial solubilization mainly depended on oil availability vs. lyc amount. Thus an improved TP_SFE_CO2 was designed in which 703 g of exogenous tomato oil will be fluxed from the co-solvent tank: the new process will produce 884 g kg-1 d.m. of extract with an expected recovery of 99.3% of the extractable lyc (lyc = 502 µg g-1 oil).