MICROWAVE PROCESSING UMARI NECTAR (PORAQUEIBA SERICEA TULASNE): BIOACTIVE COMPOUNDS AND QUALITY PARAMETERS

Umari, Porqueiba sericea, is an indirect source of vitamin A, as they contain provitamin A carotenoids that are converted into vitamin A in the human body. The potential offered by umari for industrial use is based on the feasibility of producing abundant material, with technology available and accessible to the socioeconomic conditions of the Amazonians and adapted to the infertile soils of the Amazon. Umari grows and bears fruit quickly, starting at three years old, its life cycle exceeds 80 years.
Innovative food processing technologies have been extensively investigated in the food processing industry in recent years. Microwave heating has been considered a promising technology for continuous flow thermal processing of fluid foods due to better quality retention. Its application to food treatment as an alternative to the conventional heating method is increasingly the subject of scientific studies and tests. This technology has mainly been applied for heat treatment and concentration of fruit drinks.
One of the goals of heat treatments in the processing of fruit juices and pulp is the inactivation of enzymes such as peroxidase (POD) and polyphenol oxidase (PPO). To date, there are no studies on the use of microwaves on Poraqueiba sericea nectar. The present study aimed to evaluate the effect of microwaves (10, 20, 40 and 80W, for 10, 20, 40 and 60s) on quality parameters and bioactive compounds.
The nectar was processed using a mechanical shaker for 5 minutes and subjected to microwave pasteurization. The samples were heated in microwaves at the maximum power of 10, 20, 40 and 80 W, at intervals of 10, 20, 30, 40 and 60s, a control sample was performed without treatment. Immediately, the flasks were removed, closed, and cooled in an ice bath (4°C) to room temperature.
The impact of microwave heating on the quality parameters and bioactive compounds of Poraqueiba sericea nectar compared to the untreated sample was evaluated, for which physicochemical and quality parameters were analyzed (moisture, protein, lipids, carbohydrate, energy value, pH, acidity, soluble solids and cloud value), beta carotene, fatty acids, enzymes (PPO and POD), minerals and color parameters (L *, a *, b * and ΔE*).
Microwave heating (MW) in the processing of Poraqueiba sericea nectars maintained the quality parameters, mainly with improved cloud values. Processing increased the concentrations of bioactive compounds, which could be more bioavailable to be absorbed during digestion but reduced the concentration with increasing processing temperature. Peroxidase and polyphenol oxidase were significantly reduced in the microwave heating process. Microwave heating for nectar is beneficial as it improved the quality of the nectar without inducing any change in its physicochemical parameters. Evidence shows that microwave heating is a viable technology for processing Poraqueiba sericea nectar compared to conventional heat treatments.