Nina Natacha Sophie NGONO EYENGA^{1, 2}, Ornela Ingrid TIENTCHEU PATIPE¹, Aymar Rodrigue FOGANG MBA^{1, 3,}, Adelaide DEMASSE MAWAMBA³, Nicolas POLICARPE NOLLA³, Fabrice Fabien DONGHO DONGMO³, Pauline MOUNJOUENPOU², Germain KANSCI¹

Despite their high nutritional value, the large-scale industrial application of African palm weevil (Rhynchophorus phoenicis) larvae is hindered by limitations regarding stability and preservation. This study evaluated the effect of spontaneous fermentation on the nutritional and anti-nutritional composition, physicochemical, technofunctional characteristics and microbiological profile of Rhynchophorus phoenicis larvae paste, with a view to improving its suitability as a food ingredient. The larvae were dry-salted (15%), ground into a paste, and subjected to a two-stage fermentation (7 days + 30 days of maturation). Fermentation modified the proximate composition of the paste. The protein content increased at the beginning of the process, reaching 37.3 g/100 g (day 7), while carbohydrates significantly decreased, reflecting their consumption by microorganisms. Lipids remained the dominant fraction at the end of fermentation (up to 53.4 g/100 g), providing the paste with a high energy density (up to 616 kcal/100 g). Calcium and iron levels showed moderate fluctuations, while zinc remained stable. Oxalates and phytates remained negligible (≤ 0.04 mg/100 g), whereas saponins decreased after the 5th day. A progressive acidification was observed (pH 6.01 to 5.85), accompanied by an increase in titratable acidity (maximum 5.75 at day 30), favoring the dominance of lactic acid bacteria, which reached a load of 10.71 log CFU/g. Regarding techno-functional properties, the water absorption properties (176 %), oil absorption capacity (141%), foaming capacity (20.40%), and foaming stability (94.70%) were optimized by the end of fermentation. These results demonstrate that fermentation constitutes an effective biotransformation tool to modulate the composition, enhance functional properties, and stabilize R. phoenicis paste.

Microbiological profile, Nutritional composition, Physicochemical properties, Rhynchophorus phoenicis, Spontaneous fermentation, Technofunctional properties