The Efficacy of Garlic and Turmeric in Extending the Shelf Life of Sun-dried Marine Sardines (Stolephorus commersonnii)

Increasing the shelf life of sun-dried marine sardines is critical to maintaining their quality and cutting down on food waste. The use of spices is common in different localities, however, there is a pressing need to optimize the use of spices for enhanced quality and shelf life of seafood. This study aimed to optimize the use of spices during the storage of sundried marine sardines. Design expert software was used for this purpose. Three levels of two independent factors were used to obtain different combinations Garlic/Allium sativum (0-3%) and Turmeric/Curcuma longa (0-3%). A linear equation was developed to indicate the relationship between variables (independent and dependent variables). The bacterial and fungal counts (cfu/mL) were reduced with increased concentrations of garlic, and turmeric, singly and in their combinations. The optimum reduction of bacteria (0 cfu/mL) and fungi (cfu/mL) was obtained with the combination of garlic and turmeric at 1.5% and 3% respectively. The bacterial count (0 cfu/mL) was observed in sun-dried sardines treated with garlic and turmeric at 1.5%, 3%, or its interactions respectively, whereas the highest bacterial count (360 cfu/mL) was observed in control. Further, the lowest fungal count (0 cfu/mL) was observed in sun-dried sardines treated with garlic and turmeric at 3% concentration only or its interactions whereas the highest fungal count (68 cfu/mL) was found in the control samples. Analysis of variance indicated that interactive effects significantly (p ≤ 0.05) affected bacterial and fungal count growth. Further results indicate that about 55% of the isolated samples were not colonized with bacteria while 25% and 20% of the isolated samples were contaminated with E.coli and S. aureus respectively. About 63% of the isolated samples showed no fungal growth, while 20% and 17% of the isolated samples were contaminated with Mucor and Aspergillus flavus respectively. Generally, optimizing the use of spices such as garlic improves quality and extends the shelf life of sun-dried marine sardines, and hence recommended for seafood preservation.