RESULTS: Three days of incubation in darkness increased saturated fatty acid (SFA) content from 34.0 to 41.4% but decreased monounsaturated fatty acid (MUFA) content from 36.7 to 29.8%. Palmitic acid (C16:0) content was increased from 23.2 to 28.9%, whereas oleic acid (C18:1) content was reduced from 35.4 to 28.8%. Total oil content was slightly decreased from 20.4 to 18.7% after 3 days of darkness, without a significant reduction in biomass compared to 3 days of incubation in light. Biomass and oil content was highest in cultures incubated for 6 days in light, however the stimulatory and inhibitory effects of darkness (or light) on SFA and MUFA content was no longer present at 6 days of incubation.
CONCLUSIONS: Findings from this study suggests that fatty acid composition in C. vulgaris could be modulated to favor either C16:0 or C18:1 by a brief period of either darkness or light incubation, prior to harvesting.
METHODOLOGY: The resulting products were compared to the control muffin, which was made with 100% butter. Muffins were analyzed for nutritional content, fatty acid profiles, and sensory acceptability.
RESULT: Muffins incorporated with avocado purée revealed a significant increase (p < 0.05) with respect to moisture, ash, and carbohydrate in comparison with the control sample. However, no significant changes (p > 0.05) were detected in all muffin formulations for protein and dietary fiber content. Both fat content and caloric value of muffins incorporated with avocado purée were significantly decreased (p < 0.05). The fatty acid profile showed that there was an increment in the monounsaturated fatty acids (MUFA) content by 16.51% at full-fat substitution. The sensory evaluation test demonstrated that muffins had acceptability at up to 50% substitution. Fat substitution at higher than 50% lead to undesirable flavor and aftertaste, which was significant (p < 0.05) to the panelists.
CONCLUSION: The findings indicated the feasibility of avocado purée in fat-reduced muffin preparation with an optimal level of 50% avocado purée substitution.