Showing papers in "Asian Journal of Food and Agro-Industry in 2012"

Production of papaya powder under foam-mat drying using methyl cellulose as foaming agent.

Abstract: Experiments were carried out to optimize the process parameters for production of papaya powder under foam-mat drying. Papaya pulp was foamed by incorporating methyl cellulose as foaming agent at different concentrations of 0.25, 0.50, 0.75 and 1.00% on w/w basis. The maximum stable foam formation was 83% at 0.75% methyl cellulose with 9°Brix pulp and whipping time of 15 min. The foam expansion was significantly influenced by pulp concentration and levels of the methyl cellulose at 1% level. The foamed pulp was dried at air temperature of 60, 65 and 70°C with foam thickness of 2, 4, 6 and 8 mm in a batch type cabinet dryer. The drying time required for foamed papaya pulp was lower than non-foamed pulp at all selected temperatures. Biochemical analysis results showed a significant reduction in ascorbic acid, β-carotene and total sugars in the foamed papaya dried product at higher foam thickness (6 and 8 mm) and temperature (65 and 70°C) due to destruction at higher drying temperature and increasing time. There was no significant change in other biochemical constituents such as pH and acidity. The sensory evaluation of the quality attributes of papaya powder juice showed significant reduction in colour, taste, flavour and overall acceptability at 65 and 70°C. The papaya powder obtained from the pulp of 9°Brix added with 0.75% methyl cellulose, whipped for 15 min and dried with a foam thickness of 4 mm at a temperature of 60°C was found to be optimum condition for production of papaya powder.

Production and characteristics of canned tempe extract

Abstract: Tempe is a traditional Indonesian food product derived from fermented soybeans using Rhizopus oligosporus. Tempe has many advantages, such as good nutritional value and organic compounds contributing to human health. Tempe’s key benefits are related to its excellent protein content, high levels of essential fatty acids, numerous vitamins and minerals, dietary fibres and isoflavones. Tempe extract (tempe milk) is an example of a diversified tempe-based food. The purpose of this study is to produce canned tempe-extract. This study determined the sterilization time, nutrition facts, isoflavone contents, antioxidant capacity and production feasibility of canned tempe-extract. The results showed that the most favourable formula was tempe extract with 7%(w/v) honey as sweetener. The time needed to sterilize the canned tempe-extract (can size 202x308) was 25 minutes after the activation of the retort to reach sterilization level equivalent to Fo value of 2.62 minutes. The sterilization process did not affect the sensory characteristics of canned tempe-extract significantly. The proximate analysis results showed that canned tempeextract contained 90.27% water, 0.06% ash, 3.66% protein, 0.98% fat and 5.03% carbohydrate. The isoflavones analysis results showed that canned tempe-extract contained total isoflavones of 5.09 mg/100g. The canned tempe-extract had antioxidant capacity of 7.13 mgAEq/150ml, which means 150 ml canned tempe-extract had equivalent antioxidant capacity to 7.13 mg ascorbic acid. The economic study showed the production of canned tempe-extract was feasible.

Application of cellulase preparation to guava mash treatment in juice processing: optimization of treatment conditions by RSM

Abstract: The objective of this study was to use cellulase preparation in guava mash treatment for improvement in juice yield and quality. Firstly, the effect of enzyme concentration and biocatalytic time on the juice yield was investigated. Response surface methodology was then employed to select enzyme dosage and treatment time for maximizing juice yield. The results showed that optimal concentration of cellulase preparation and treatment time were 0.13% (w/w) and 93 minutes, respectively. Under these conditions, the extraction yield, total sugars and phenolics level in the obtained juice increased 22.3%, 20.0% and 11.5%, respectively in comparison with those in the control sample. Although cellulolytic treatment decreased the content of ascorbic acid in guava juice, the antioxidant activity of the product was increased 21.8% in comparison with that in the control sample.