Preparation of Guava (Psidium Guajava) Jelly with Ethanolic Leaf Extracts and Assesment of its Nutritive Value, Shelf Life and Antimicrobial Efficacy Against Escherichia Coli

Abstract

Guava (Psidium guajava) is a fruit that is widely grown around the world and is well known for its therapeutic benefits in the treatment of a variety of diseases and ailments. The goal of the study was to make guava jelly with 5%, 10%, and 15% guava leaf extract (sample B, sample C, and sample D respectively) and compare it to control jelly(sample A) in terms of bioactive compounds total antioxidant content, total flavonoid content(TFC), total phenolic content(TPC), antimicrobial activity, sensory and nutritional factors. Guava leaves extract was obtained using an extraction procedure from guava leaves. The extracts are then added to processed guava jelly in proportions of 5%, 10%, and 15%. Among these formulations, the sensory score of guava jelly processed with 15% guava leaves extract (sample D) was shown to be the best. Carbohydrate, fat, protein, ash, and fiber content were measured between at the range of 60.03% to 65.23%, 1.09% to 1.29%, 0.53% to 0.70%, 0.28%to 0.36% and 1.47% to 1.78% respectively. Guava jelly has a vitamin C concentration of 26.63-28.40 mg/100g, according to estimates. In addition, Sample D had the highest concentration of total antioxidant content (3.97±0.011 mg TA/100 mL), total flavonoid content (46.25±0.005 mg QE/100 g) & total phenolic content (10.46±0.152 mg GAE/100mL). The lowest concentration of total antioxidant content (1.96±0.002 mg TA/100 mL), total flavonoid content (32.87±0.001mg QE/100 g) and total phenolic content (6.40±0.100 mg GAE/100mL) was found in sample A. At first, there was no discernible bacterial load in the jelly, but after 60 days of storage, the bacterial load rapidly grew. At 30-day intervals, yeast and mold development were studied. Incubation in Sabouraud Dextrose agar for 7 days yielded no detectable fungus growth in guava jelly. Yeast and mold infestation were identified in the jelly after 90 days of storage. Furthermore, ethanolic guava leaf extract showed antimicrobial efficacy against E.coli which can be used as a substitute of commercial antibiotics.