Process for integral use of blueberry

N. PIZZOLATO, M. ANDRADA, A.N. RINALDONI, M. E. CAMPDERRÓS

INTERNATIONAL JOURNAL OF FOOD ENGINEERING

BERKELEY ELECTRONIC PRESS

Año: 2012 vol. 4 p. 1556 - 1560

1556-3758

Blueberries, rich in anthocyanins, have long been recognized for their health benefits as antioxidant, besides they have been studied for their potential as natural colourants for food or cosmetics. A flow sheet which includes several methods for processing blueberry were performed to obtain different products. Membrane technology was applied, as a non thermal alternative for obtaining a clarified juice in the permeate stream and a blueberry concentrate in the other stream. An inorganic microfiltration membrane Carbosep® was used into a tubular Plexiglas module. The concentrate was dried by freeze-drying at -40°C and 1 bar. With the solids obtained in the pre-treatment and during the filtration of the fruit, jams were elaborated following the usual procedure. Different jam formulations were assayed: i) common grade with the addition of sugar, and ii) reduced calories, using Stevia (rebaudiana Bertoni) as a natural sweetener. The polysaccharide has many healthy properties in treating obesity and high blood pressure. A physical-chemical and sensory analysis of fruits and products has been carried out. The results showed that blueberries? clarified juice, presented colour, flavor and pleasing appearance, the presence of anthocyanins could be determined. The freeze-dried concentrate was stable, retaining a bright colour similar to the fruit and can be quickly re-hydrated. The manufactured jams showed similar characteristics to commercial products (pH: 3.5; soluble solids: 67.5 °Brix; ash: 7.4 % w/w). The sensory analysis indicated that the formulation with sugar /Stevia: 50-50%, was rated significantly better than mixtures 25-75% or 100% Stevia. The process allows an integrated use of the fruit obtaining products with high nutritional quality.