Membrane Technology for Valorization of Mango Peel Extracts

Mango Peel Nanofiltration Concentrates to Enhance Anaerobic Digestion of Slurry from Piglets Fed with Laminaria

The environmental impact of biowaste generated during animal production can be mitigated by applying a circular economy model: recycling, reinventing the life cycle of biowaste, and developing it for a new use. The aim of this study was to evaluate the effect of adding sugar concentrate solutions obtained from the nanofiltration of fruit biowaste (mango peel) to slurry from piglets fed with diets incorporating macroalgae on biogas production performance. The nanofiltration of ultrafiltration permeates from aqueous extracts of mango peel was carried out using membranes with a molecular weight cut-off of 130 Da until a volume concentration factor of 2.0 was reached. A slurry resulting from piglets fed with an alternative diet with the incorporation of 10% Laminaria was used as a substrate. Three different trials were performed sequentially: (i) a control trial (AD₀) with faeces resulting from a cereal and soybean-meal-based diet (S0); (ii) a trial with S₁ (10% L. digitata) (AD₁), and (iii) an AcoD trial to assess the effect of the addition of a co-substrate (20%) to S1 (80%). The trials were performed in a continuous-stirred tank reactor (CSTR) under mesophilic conditions (37.0 ± 0.4 °C), with a hydraulic retention time (HRT) of 13 days. The specific methane production (SMP) increased by 29% during the anaerobic co-digestion process. These results can support the design of alternative valorisation routes for these biowastes, contributing to sustainable development goals.

Impact of Water Supply Reduction and Cold Storage on Phenolic Compounds from Mango (Mangifera indica L. cv. Cogshall) Pulp and Peel

The impacts of water supply reduction and cold storage were investigated on the peels and pulps of cv. Cogshall mangoes, regarding their phenolic compound contents. Phenolics identification was operated using HPLC-MSn for both compartments revealing an unbalanced repartition. Peels had a richer and more complex profile, counting xanthone glycoside (mangiferin), flavonoids (quercetin, kaempferol) and majorly gallotannins. Pulps presented smaller amounts of phenolics and a simpler profile majorly represented by gallotannins and gallic acid derivatives. During fruit ripening, the phenolic contents decreased in both compartments, but faster in the pulp. This behavior can be attributed to the oxidative stress observed in mango pulp during ripening. Cutting down the water supply during the fruit growth triggered an increase in phenolic contents of both the peels and pulp of mango fruits. This increase affected all compounds. Cold storage at 12 or 7 °C led to an increase in mangiferin and flavonoids contents in the fruit peel, interpreted as a stress-response reaction.