Storage Stability and Sensory Properties of Soft-Dough Biscuits Incorporated with Hard-Dough Biscuit Powder

In biscuit production, non-conforming products resulting from minor deviations are ground into powder and reused as an ingredient in new manufacturing cycles. This study aimed to assess the storage stability of hard dough biscuit powder (HDBP) and the sensory properties of HDBP-incorporated soft-dough biscuits (SDB). HDBP was stored for 5 weeks, and soft-dough biscuits (B1, B2, B3, B4, and B5) were made from the stored HDBP each week, with freshly ground HDBP used as the control. The SDB were stored under accelerated conditions (40 °C, 90% RH) for 7 weeks. Weekly measurements were taken for moisture content, pH, free fatty acids (FFA), peroxide value (PV), and p-Anisidine in both stored HDBP and SDB. Total plate count, yeast and molds, Escherichia coli count, and sensory properties were determined in stored SDB. The moisture content of HDBP stored for 5 weeks was higher (7.60±0.51%) compared to all the other weeks (p<0.05). pH and PV variation was not significant (p>0.05) during the storage of HDBP. The sensory properties of B1, B2, and B3 were not significantly different (p>0.05) under accelerated conditions for 5 weeks compared to the control. Moisture, FFA, PV, and p- Anisidine value had a strong positive relationship with storage time in SDB stored for 7 weeks under accelerated conditions. Having acceptable moisture content, pH, FFA, PV, and p-Anisidine value, HDBP stored for up to 4 weeks can be used as an ingredient in biscuit manufacturing. However, the SDB manufactured using HDBP stored for up to 2 weeks had the best sensory properties and acceptable microbiological quality. Therefore, biscuit powders stored for up to 2 weeks with desired physicochemical, microbiological, and sensory properties are recommended to be used as an ingredient in the biscuit manufacturing process.