Effect of honey and lemon juice on the physicochemical, nutritional, minerals, color, bioactive compounds, antibacterial and antioxidant properties of guava-pineapple jelly

Abstract

Abstract Background Jellies are usually preserved by artificial preservatives where they have harmful side effects and health hazards especially to infants. Honey and fresh lemon juice work as natural preservative due to their hygroscopic, high sugar, low pH and antibacterial properties. Hence, the honey and fresh lemon juice were undertaken to formulate the synthetic preservative free guava-pineapple jelly for extended shelf life with higher retention of nutrients and antioxidants. Results Best formulation found using honey and fresh lemon juice treated jelly (T2 and T3) by the sensory evaluation, nutrients, bioactive compounds, phenolics, antioxidant and antibacterial properties. Storage study was conducted at ambient condition and the shelf life of the jelly was remained upto 8 months without any quality deterioration. All the physicochemical, nutritional, minerals, bioactive compounds, antioxidants activities and phenolic acids were decreased with progression of storage periods. The highest vitamin-C, energy, total phenolic, flavonoid, carotenoid, ß-carotene, and anthocyanin, were recorded by the combination of guava-pineapple jelly formulated using honey and fresh lemon (T3) juice; values were 42.94-41.00 mg/100 g, 406.35-406.94 cal/g, 4.15–4.01 mg GAE/100g, 0.91 − 0.84 mg QE/g, 0.94 − 0.84 mg/100g, 12.44–12.20 mg/100g, and 4.06–4.01 mg/100g, respectively. Phenolic acids, i.e. gallic acid, vanilic acid, caffeic acid, ferulic acid, catechin acid and syringic acids were identified and quantified higher in sample T3; values ranged 5.41–5.30 mg/100 g, 4.66–4.54 mg/100 g, 9.07–8.93 mg/100 g, 0.46 − 0.35 mg/100 g, 81.70-81.43 mg/100g, 3.23–3.10 mg/100 respectively. Microbial study confirmed that the jelly was free from microbes upto 6 months of storage. After 8 months, the Aspergillus, Shigella and E-coli were detected but they were within acceptable limit. Initial color was retained upto 8 months of storage but after 8 months, the color faded out and turned into dark. Conclusion Honey and fresh lemon juice are valuable source of natural preservative for formulation of fruit jelly with extended shelf life upto 8 months by preventing microbial activities. The processors could process and preserve the fruit jelly with decent aroma by applying this technology as an alternative to artificial food additives.