Insights into effectiveness of tight ultrafiltration and frozen storage in bioactive compound retention in watermelon juice concentrate

Abstract

The aim of this study is to evaluate the potential of tight ultrafiltration for the concentration of bioactive compounds in watermelon juice and also analyze the effectiveness of frozen storage for storing the juice concentrate. The concentration of the juice was performed at two different temperatures of 30 ± 2 C and 23 ± 2 C and at pressures of 2 and 3 bar for concentration factors of 1.5, 2, and 3. Total phenolic content in the concentrate was determined in terms of gallic acid and flavonoid concentration was analyzed in terms of rutin equivalent. Lycopene was determined spectrophotometrically using the hexane extraction method. The ultrafiltration (UF) process was successful in retaining a high percentage of bioactive compounds in the watermelon juice concentrate. Flavonoids showed the highest levels of concentration among the four important bioactive compounds. The ultrafiltration experimental set of T = 23 ± 2 C, P = 3 bar and volumetric concentration factor = 1.5 was found to be most feasible. Frozen storage at −18 C was successful in retaining a high percentage of bioactives in the concentrate after 1 month although vitamin C loss was on the higher side. Lycopene was highly preserved in the concentrate juice after frozen storage with retention of 93%.

Mechanisation of the primary processing of watermelons without destroying the rind

“…Watermelon is a vitamin food product containing ascorbic acid, easily digestible sugar, vitamins, folic and malic acids, trace elements that provide a positive effect on the human body (Bhattacharjee et al, 2020;Artés-Hernández et al, 2021). The content of dry soluble substances in watermelons -13.5%, sugars (glucose, fructose, sucrose) -14%.…”

Sustainable Drying and Green Deep Eutectic Extraction of Carotenoids from Tomato Pomace

“…As for lycopene, β-carotene has also seen a major demand, reaching high prices (more than 500 EUR per kg), making tomato pomace a profitable source of this important biological compound [38,39]. Moreover, traditional solvent extraction may have low efficiency with consumption of large amounts of solvent and time [40][41][42]; moreover, the solvents may be harmful for both the environment and human health [43,44]. Organic solvents can easily enter body parts and organs, where they are converted via osmotic processes into water-soluble forms, which sometimes can be more toxic than the parent compound [45].…”