Valorisation of frozen chestnut by-products: technological challenges for the production of gluten-free flour

Abstract

The industrial process of freezing chestnuts generates 55-60% of by-products. This study aimed to valorise these low-value by-products by producing high-value chestnut flour. Two flour production processes were evaluated, using raw (RCF) and cooked (CCF10, CCF30, CCF50) chestnut by-products during 10, 30 and 50 min. The highest production yield was obtained for RCF (43.6 ± 1.0%) followed by CCF10 (38.0 ± 1.0%). Regarding flour composition, CCF50 presented the smaller protein, fat, fibre and ash contents (P < 0.05). For colour, a w , pH and sedimentation index, no significant differences were observed namely between RCF and CCF10 (P > 0.05). The CCF10 flour also presented the smallest particle size. The highest peroxide index was found in CCF50 penalizing its acceptance by consumers due to the evidence of rancidity, emphasizing that long time-periods of cooking must be avoided. Finally, up to 129 days of storage, under no temperature or lighting controlled conditions, all chestnut flours showed to be stable overtime.

Evolution of control parameters in biochemical methane potential tests of olive mill solid waste (OMSW), thermal pre-treated OMSW, and its co-digestion with Dunaliella salina

“…This recycling strategy not only avoids disposal cost and environmental issues, but also brings a valorization pattern to the agricultural and agro-industrial sectors (Muchagato et al, 2018). The valorization of by-products is a trend that is in progress and has been increasing its value in the last decade (Borges et al, 2019, Meini et al, 2019. The olive oil industry is one of the main agro-economic activities in Spain and this is a sector that is booming worldwide.…”