Improving Characteristics of Frozen Yogurt enriched with loquat leaves extract

Abstract

Frozen yogurt is a fermented frozen dairy dessert that blends the physical qualities of ice cream with the sensory and nutritional benefits of fermented milk items. In this study, the formulation of frozen yogurt was enriched with 1% loquat leaves extracted using 30, 70 and 90% ethanol. The final product was evaluated for physical characteristics (pH, total acidity, melting rate and, color), total phenolic content, microbiological analysis, and sensory evaluation. The obtained results illustrated that; 90% leaves extract has the highest flavonoids content (1.023 mg QE/g). The major phenolic compound was the pyrogallol was observed with 70% ethanol extract. The results showed that, all supplemented frozen yoghurt samples were effective against all tested microbial strains at the level of all loquat extracts. The lowest MIC values observed with the samples contained 30% ethanol extract loquat at 5.0 μg/μl for Staphylococcus aureus and Escherichia coli. Data also indicated that, the control sample recorded the highest pH value (4.67) and was the fastest in melting. Additionally, the a* values of frozen yogurt with 90% ethanol extract were lower, meanwhile b* values were higher. The same samples had a significant higher amount of total phenolic content by 3.04 times compared with the control sample. The control frozen yogurt registered the highest value of total plate count (30x102cfu/g). The highest score of texture was 9.0 and 8.95 for frozen yogurt enriched at the level of 90 and 70% ethanol extracts .