Processamento de suco semi-clarificado e de geleia de banana "light" em calorias

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

The banana is the most popular fruit on the latin american continent. World production of the fruit is around 50 million tons, of which Brazil produces 11 %, being the second largest producer. In 1996, brazilian exportations of banana represented only 1.5% of the national production, and in january 1997, the brazilian producer received only $0.34/dozen bananas on the internal market. Thus, the banana is a very cheap fruit, but at the same time, a rich source of calories. The idea of this research was to obtain a calorie light banana jam, a product presenting aggregated value. No mention of such a product was found in the literature, and the objective of the research was achieved. Jams were formulated with and without a mixture of sucrose substitutes consisting of sorbitol, fructose and polydextrose, receiving average grades for global flavor quality between 5.36 and 7.00 and for texture between 5.88 and 7.49. The jam formulated with the substitutes and with the lower level of fruit solids presented the highest average values for global flavor and texture. Preliminary experiments were also carried out with respect to the production of the semi-clarified banana juice from the puree. Banana juice is easily found on the european, north american and argentine markets, but is not available on the brazilian market. In these experiments, different ways of reducing the length of the enzymatic hydrolysis step, thus reducing processing costs; of obtaining semi-clarified juice with properties very similar to those of the natural fruit and of obtaining juice with reduced levels of sucrose and glucose, thus making its use feasible in diets in which these sugars are restricted, were studied. Processing the puree did not affect the proximate composition (moisture, protein, lipid, ash and total carbohydrate contents) or the pH, as compared to the natural fruit, but resulted in an increase in brix from 21 to 22.7. The use of an industrial pectinase preparation, incubating for 20 minutes at 45°C, resulted in an increase in yield of 38%, when compared with that obtained without the addition of enzyme, incubating for 120 minutes at 45°C. Increasing the incubation time with enzyme from 20 to 120 minutes resulted in an additional increase in yield of 6% (from a total of 65 to 71.2%). The hydrolysis of the 9.26g of sucrose contained in 100 mL semi-clarified banana juice (pH 4.43), obtained using the pectinase Clarex, was completed by incubating with 0.6% Invertase-S for 15 minutes at 40°C. In this way, semi­clarified sucrose free banana juice was obtained. The average values for yield, absorbance and pH of the semi-clarified, sucrose free banana juice did not vary (p>0.05) with the temperature (40, 50 and 60°C) and time (15, 20 and 25 minutes) used, although the brix presented significant differences (p<0.05) as a function of these variables. The juices obtained with industrial enzymes (Clarex, Clarex &Invertase-S and Clarex &Invertase &Taka-sweet) presented greater yields and brix values and lower viscosities and pH values than those obtained with laboratory produced enzymes (CTM pectinase and Sigma pectinase and cellulase). The isomerization of the extra 0.19 9 glucose (extra as compared to the amount of fructose), contained in 100 mL semi-elarified sucrose free juice, was completed by incubating with 0.5% glucose isomerase (Taka-sweet) for 15 minutes at 40°C. There was no significant difference in the averages for fresh banana aroma between the juices, the values all being close to the center of the scale used. The level of alcoholic aroma was considered to be low and did not vary between the treatments. The addition of invertase resulted in a considerable increase in sweetness accompanied by an increase in viscosity of the juice. The juices presented mesophilic and yeast and mold counts well below those cited in the literature. Sensorially, the juice which presented the most equilibrated composition with respect to acids and sugars, was that obtained with Clarex. The grades for global flavor of the juices varied from 5.44 to 6.72 and those for the proportion of yellow from 2.94 to 8.55

ASSUNTO(S)

avaliação sensorial banana pectinase geleia

ACESSO AO ARTIGO

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