Insect flour as milk protein substitute in fermented dairy products

Abstract

Fermented dairy products (FDP) are consumed worldwide, due to their nutritional attributes and sensory properties. In the last decade, edible insects have been the subject of research as a sustainable source of protein to be introduced into the food industry. The mealworm (Tenebrio molitor) and buffalo worm (Alphitobius diaperinus) have demonstrated the highest consumer potential. However, this study aims to demonstrate the effectiveness of other possible options such as black soldier fly (BSF) and drone brood (DB) flours in FDP, with or without probiotics, as a viable substitute of milk powder during refrigerated storage for 21 days. The nutritional composition of the products remained unchanged despite the addition of insect flour, with a fat content of ∼0.95% and a protein content of ∼4.7%. The products acidity increased from 0.78% to 1.06% lactic acid during storage. The colour of the FDP was typical yellowish-white, except for those containing BSF flour which had a darker colour. For all FDP, syneresis values were below 10% after the first day of storage, particularly for those with DB flour with syneresis as low as 5%. The probiotics had the highest values of Lactobacillus spp. (>6 log CFU/g) and Streptococcus spp. (>10 log CFU/g). The addition of the BSF flour was found to have a negative impact in the consumers’ perception of the products, according to the sensory analysis.