Antioxidant pectins and fibers rescued from agro-industrial residues useful for food preservation

ROJAS A.M.; BASANTA M. F.; PEREZ, C.D.; ROSSETTI, L.; IDROVO ENCALADA A.M.; FISSORE E. N.

Paris

Conferencia; 7th International Conference on Food Chemistry & Technology (FCT-2021).; 2021

USG United Scientific Group. A non-profit organization. foodchem@uniscigroup.org

Advanced valorization strategies involve the generation of multiple products by extraction of valuable components or chemicals. Agro-industrial by-products can be applied to the extraction of total fibers and pectins carrying co-extracted antioxidants, useful for preservation of healthy processed foods. The polysaccharides (dietary fibers) from the cell-wall have functionalities of technological interest in food formulation. Alcohol or water insoluble total fiber fractions were separately obtained from discarded plums (peel and flesh) and cherries. As they carried extractable phenolics, proantocyanidins, tocopherols, and carotenoids, cherry fibers preserved milk from protein oxidation in a concentration-dependent manner (0-9% w/w), while plum fibers (2.5% w/w) preserved chicken patties from lipid oxidation (12-days-refrigerated storage. On the other hand, a pectin fraction (CP) was obtained from discarded carrots by treating the sugar-exhausted water-insoluble residue with a bacterial hemicellulase (citrate buffer, pH 5.2) after applying high-power ultrasound (20 kHz, 80% amplitude, 20 min net time; 12.27 W/cm2 Power intensity). CP contained 50% of uronic acids, which were 42% methyl-esterified and 14% acetylated (molar ratio). The mechanical spectrum of 2.0% w/v CP-aqueous solution with Ca2+ (30 mg/100g uronic acids) revealed a true gel with G? = 400 Pa. The significant contents of carotenoids and ?tocopherol gave orange-color and antioxidant capacity to CP when evaluated on a 20:80 w/w chia-oil/water emulsion (45 d storage, 25ºC), and on a cashew vegan cheese (60 d storage, 7ºC) covered by a 100%-CP edible film, which was water-resistant probably due to the lipophilic antioxidants.