Green innovation in bakery: Ice cream wafer sheet made with green lentil flour and processing by-products

Currently, by-products from the lentil processing industry, mainly composed of hulls, germ, and fragmented cotyledons, are wasted or partially used in the feed industry. This study aimed to develop wafer sheets using 100% green lentil flour (LF) and 100% green lentil waste flour (LW). Both flours were first characterised in terms of chemical composition, physical, thermal, and functional properties. Two wafer formulations (% w/w) were developed using: LF or LW (26.6%; 23.9%), water (39%; 45%), sugar (12.6%; 12.3%), eggs (11.7%; 10.5%), oil (9.2%; 8.8%), salt (0.2%), vanilla flavour (0.4%). The wafer sheets (LFW and LWW) were analysed for chemical-physical, nutritional (including estimated glycemic index, anti-nutritional factors), and mechanical properties. LF and LW showed excellent nutritional profiles, particularly low glycaemic indices (45.9 and 43.7), high protein content (28.02% and 24.72%), and high fibre content (22.36% and 34.55%), respectively. LW exhibited significantly higher WHC and OHC values (p ≤ 0.05), whereas LF showed a significantly greater enthalpy change (ΔH) during starch gelatinisation. Moisture content and pH of the wafer sheet were influenced by flour type, while the water activity was similar and low (0.31–0.34). Nutritionally, LW Wafer had significantly lower total starch content than LFW. The hardness values were lower in LW wafer sheets due to the higher fibre and moisture contents. All samples contained protease inhibitors, proteinaceous in nature, very low haemagglutination activity, and reduced phytic acid levels in baked products compared to flours. Overall, the findings highlight the promising potential of these lentil-derived flours for use in the bakery sector.