Impact of red flour beetle Tribolium castaneum (Herbst) infestation in wheat flour on benzoquinone levels and biscuit quality

Abstract

The red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae), negatively impacts the quality of wheat flour and its derived products. This study examines the effects of T. castaneum infestation at levels of 10, 20, and 40 pairs/kg over different storage periods (4, 6, and 8 months) on biscuits produced by infested flour. Key parameters assessed include moisture content, weight, diameter, thickness, spread ratio, sensory attributes, chemical composition, and benzoquinone accumulation. Results indicate that biscuit moisture content and weight increased with both infestation level and storage duration. After 8 months, the highest infestation level (40 pairs/kg) resulted in a moisture content of 10.75 % and a weight of 14.40 g, significantly higher than the control. Diameter increased while thickness decreased, leading to an increase in the spread ratio from 3.89 to 4.63. Sensory evaluation revealed a decline in appearance, taste, and aroma, negatively impacting overall biscuit quality. Chemical composition analysis showed an increasing trend in crude protein, crude lipid, and ash, while carbohydrate and fiber were decreased, and this attributed to insect infestation level and biscuit formulation. Additionally, Tribolium castaneum infestation raises benzoquinone (BQ) levels in wheat flour and its biscuits, with higher insect density increasing BQ secretion, which peaks between 4 and 8 months of storage. Statistical analysis confirmed significant differences across all tested parameters. These findings highlight the progressive deterioration in biscuit quality and safety due to T. castaneum infestation, emphasizing the need for preventive strategies to minimize economic losses and maintain product integrity.