The influence of the application of commercial carbohydrases on the extraction and characteristics of strawberry tree fruit pulp

Abstract

Arbutus unedo's fruits have a high content of sugars (40%), antioxidants, vitamins such as vitamin C, β-carotene, niacin, tocopherols and organic acids. However, pulp extraction yield by conventional methods is low corresponding approximately to 42%. This study aims to evaluate the potential use of two commercial carbohydrases, Viscozyme® L and Pectinex® Ultra SP-L for pulp extraction from strawberry tree fruit and their influence on the physicochemical and rheological characteristics of the recovered pulp. Carbohydrases enzymes were tested under different temperatures (20 ºC to 25 ºC and 45 ºC), enzime concentration (1, 2 and 4 μL/g of macerated fruit) and reaction time (30 and 60 min). The same conditions were applied for control samples without enzyme addition. Pulp extraction yield (g of extracted pulp /100 g macerated fruit), apparent viscosity (at 20 ± 0.1 ºC), color, titratable acidity, pH, soluble solids (ºBrix), and total solids were assessed. The pulp with lower apparent viscosity (0.88 ± 0.38 Pa.s) was obtained by applying Viscozyme® L at 4 μL/g, 45 ºC after 30 minutes of incubation. Pectinex® Ultra SP-L was responsible for the highest pulp extraction yield (54.9 ± 1.1%) after 30 min, at 2 μL/g and 45 ºC. It was also responsible for the highest soluble solids content (27.3 ± 0.1 ºBrix) at room temperature (20 ºC to 25 ºC), after 60 min at 4 μL/g. No significant differences (p > 0.05) were found for the remaining physicochemical characteristics of the extracted pulps under the tested conditions. Carbohydrases-assisted extraction methodology provided promising results to increase the portfolio of added value products from strawberry tree fruit with high potential application in the food industry (fruit beverages, jams, ice creams, among others).

Keywords:
Arbutus unedo L.; Pulp extraction yield; Viscozyme® L; Pectinex® Ultra SP-L; Viscosity; Soluble solids (ºBrix)