Development of processing technologies for dragon fruit

Date

2016

Abstract

The study was conducted to utilize red-fleshed dragon fruit into a fruit juice drink. Four formulations of fruit juice drinks were developed: 1:3, 1:5, 1:7, and 1:10 juice to water ratios. The pH and the total soluble solids (TSS) were maintained at 3.6 and 12 deg C Brix respectively. Treatment A which has the highest amount of dragon fruit juice in the formulation obtained the highest values for total titratable acid (TTA) and Vitamin C content. This is due to the inherent organic acids and vitamins present in the dragon fruit. In terms of viscosity, a significant difference was detected among samples; treatment A being the most viscous and treatment D as the least viscous. The higher the amount of fruit juice in the sample, the higher the concentration of the solutes is, which resulted in a more viscous product. Using the chromameter, an increasing trend for the color parameters L*, a* and b* values was observed as the dilution increases. Treatment D resulted in the highest values for all the parameters while Treatment A got the lowest values. Sensory evaluation showed that color differed among all treatments. Resulting in the most intense magenta color for treatment D. A significant difference was also observed among samples in terms of aroma and flavor, and the strongest perceived treatment was treatment A, whereas the weakest was treatment D. Consequently, there was no significant difference observed among treatments in terms of sweetness, sourness, and off-flavor. The most generally acceptable dragon fruit juice drink formulation was treatment B which has 1:5 fruit juice to water ration and the total cost of the product per bottle is PhP 19.43. Dragon fruit was utilized as a flavouring agent for a cream cheese spread. The fruit was processed into jam and puree and was incorporated in the cream cheese in varying formulations: 0%, 5%, 10%, 15%, 25%, and 35%. Results show that there was no significant difference among the formulation in terms of general acceptability, aroma, and aftertaste; hence, the 35% formulation was chosen due to its lower price. The cheese spread, which was light gray in color, was subjected to chemical tests. Results revealed that it has 8.00 mg and 7.33 mg ascorbic acid per 100g sample for puree and jam treatments, respectively. The antioxidant activity results showed that the puree had the higher antioxidant activity, which is around 68.54% compared to the jam's 60.60%. Viscosity tests revealed that the cream cheese spread flavoured with jam was the most viscous, with its viscosity at 6.33 x 105 cP; and the puree’s viscosity which was 5.75 x 10 sup 5 cP. The prospect for functional foods like yogurt is high and through the years there has been an increase in demand for yogurt with lower viscosity. On the other hand, tons of dragon fruit are rejected annually due to pest. To solve this problem, it is desirable to promote the use of dragon fruit as ingredient to functional food specifically yogurt drink. This study was conducted to develop a dragon fruit (Hylocereus polyrhizus) –flavored yogurt drink. Yogurt drink was added with different dragon fruit puree concentrations (0, 5, 10, 15, and 20%). The physicochemical, antioxidant and sensory properties of each treatment were determined, analyzed and compared. The results indicate that the pH increases and the titratable acidity (TA) expressed in lactic acid decreases as the dragon fruit puree concentration increases since the dragon fruit is less acidic compared to the pure yogurt drink. Consequently, the total soluble solids (TSS) increases as the dragon fruit puree concentration increases due to the high total soluble solid of the dragon fruit puree. There was a decrease in viscosity (cP) as the dragon fruit puree concentration was increased in the formulation. The color values, red, blue and green, generally decreases with increasing concentration of dragon fruit puree. Dragon fruit is said to be an excellent source of antioxidants and the antioxidant activity through % DPPH scavenging assay test showed that there is an increasing trend in antioxidant activity as the dragon fruit concentration in yogurt drink increased. Sensory analysis results showed that the highly acceptable formulation in yogurt drink was 15% dragon fruit puree although it was not significantly different with the 10% and 20%. The physicochemical, antioxidant and sensory properties revealed that the most acceptable treatment was the yogurt drink with 15% dragon fruit puree.

Language

English

Document Type

Article

Pages /Collation

80 leaves

En – AGROVOC descriptors

HYLOCEREUS; VARIETIES; FRUIT; CACTACEAE; FLAVOUR; FOOD PROCESSING; FOOD TECHNOLOGY; FRUIT JUICES; PLANT EXTRACTS; PROXIMATE COMPOSITION; ORGANOLEPTIC ANALYSIS; ORGANOLEPTIC PROPERTIES

This document is currently not available here.

Share

COinS