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FSB1 – 2004 Food Science and Biotechnology in Developing Countries We used two varieties of fresh sliced fruit: grafted and creole. As inhibitors were used solutions: salt (9%), sugar (14%), citric acid (0.5% and 1%), ascorbic acid (0.5% and 1%) and its combinations. The fruit was submerged in the solutions by 50 min. The peroxidase and catalase activities were evaluated by the method proposed in (2 and 3), in addition to color change in the exposition to air for 24 and 48 h. The positive control was fruit submerged in distilled water. The negative control was sterilized fruit. Statistical analysis The experimental data were analyzed statistically by analysis of variance, for statistical significance (α= 0.050) using LSD test (Statistical Analysis System, SAS). Results and discussion Table 1 shows the results from color change at 24 hours in exposition to air, peroxidase and catalase tests. Table 1. Color change, peroxidase and catalase probe. PEROXIDASE CATALASE Color change at 24 hr in exposition to air AGENT CREOLE GRAFTED CREOLE GRAFTED CREOLE GRAFTED Salt 9% + + + + - - Sugar 14% + + + + + + Salt-sugar - + + + - - Salt-sugar- ascorbic - - + - - - Salt-sugar- citric - - + + - - Sugar - citric + + + + + + Sugar - ascorbic + - - + + + Salt- ascorbic + + + + - - Salt - cítric - - + + - - Salt-sugar-citric 0.5%-ascorbic 0.5% - - + + - - Salt/sugar-citric 1%-ascorbic acid 1% - + + + - - Ascorbic acid 1% + - - + + + Citric acid + + + + + + Positive control + + + + + + Negative control - - - - - - There was significant difference between the 2 fruit types. The creole´s enzymes were more resistant. To inhibit the peroxidase, the best treatments were salt-sugar-citric acid and salt-sugar-ascorbic-citric acid; to inhibit catalase was salt-sugar-ascorbic acid. The worst treatment to inhibit these enzymes was salt, although in color change in exposition to air, it was the best one. In the figure 1, it is shown some of the treatments applied. The peroxidase is more sensitive to these chemical agents, and the catalase may be not so involve in the enzymatic reaction, because of the results presented in the table. The peroxidase and catalase are not the only enzymes that are involved in this reaction, because in some treatments, the exposition to air did not change the color of the hawthorn and the tests of these enzymes were negative.
FSB1 – 2004 Food Science and Biotechnology in Developing Countries Conclusions Figure 1. Some treatments applied to hawthorn, at 24 h to air exposition. Salt, Salt-sugar-ascorbic, Salt-sugar-citric, Salt-ascorbic, Salt-citric, Salt-sugar-citric 0.5%-ascorbic 0.5% and Salt-sugar-citric 1%-ascorbic 1% treatments presented good results to avoid the color change ought to the exposition to oxygen and mechanical damage, enzymatic browning. The combination of these antioxidants with salt had good effect in the inhibition of the enzymatic browning; combination of sugar with ascorbic and citric acids dif not inhibited the reaction. The acids alone did not inhibit this reaction. The enzymes tested are not the only involved in the enzymatic browning of hawthorn. It is necessary to test the polyphenol oxidase too. The variety of hawthorn have effect, is more inhibited the creole than the grafted, may be ought to the porosity and the chemical composition. References 1. Anese M. Nicoli M.C. Dall’aglio G. Lerici C. 1995. Effect of high pressure treatments on peroxidase and polyphenoloxidase activities. J. Food Biochem. 18: 285-293. 2. Braverman J.B.S. 1976. Introducción a la Bioquímica de Alimentos. Ed. Manual Moderno pp. 283- 291. 3. Estudio de la actividad de la peroxidasa, pectinesterasa y polifenoloxidasa en extracto enzimático de sandía (Citrullus vulgaris Schard). Comunicaciones Científicas y Tecnológicas. Laboratorio de Tecnología Industrial III - Laboratorio de Química Analítica Instrumental. Facultad de Agroindustrias - UNNE. Argentina. 4. Avallone C.M. Cravzov A.L. Montenegro S.B. Pellizzari, E.E. 2000. Estudio de la actividad de polifenoloxidasa y peroxidasas en Carica papaya L. mínimamente procesada. Comunicaciones Científicas y Tecnológicas. Lab. de Tecnología Industrial III y Lab. de química Analítica Instrumental - Facultad de Agroindustrias - UNNE. Argentina. 5. Desrosier N.W. 1963. Conservación de Alimentos. Segunda edición. CECSA. pp. 361.
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Determination of the effect of the
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. Texture attributes of sabila cube
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