Cultivares, variaves de processo, reuso do xarope de sacarose e viabilidade economica da pre-secagem osmotica de pessegoa / Cultivars, process variables, reuse syrup and economicv feasibility of the osmotic pre-driyng of peaches

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The objective of the present study was to evaluate the industrialization of peach cultivars from the State of São Paulo, Brazil, in the semi-dried form, using a combined process involving osmotic pre-drying (OPD) and conventional hot air drying (CD). The aptness of the cultivars Douradão, Régis, Aurora-1 and Diamante was evaluated, using OPD with sucrose syrup (65 °Brix, 45 °C, 6 h) followed by CD (65 °C, 1.5 m/s). The cultivars Regis and Aurora-1 showed the best overall performances (ease of preparation, good process yield and good sensory acceptance). A central compound rotary design was used to investigate the influence of temperature (30 / 50 °C) and sucrose concentration (45 / 65 ºBrix) in the OPD of the Aurora-1 cultivar (slices and halves). The physical and chemical variation of the fruits, the mass loss (ML) and water loss (WL) parameters, and the sensory performance of the products were investigated. The results were modeled using response surface methodology, obtaining the following significant (p<0.05) and predictive mathematical models: for the slices - soluble solids contents, total and non-reducing sugar contents, titratable acidity, L* of color and WL; and for the halves - soluble solids contents, L* of color, WL and ML. The highest values for WL and the best sensory performances were obtained in the following ranges: for the slices - 50 to 54.1 °C and 45 to 65 °Brix; and for the halves - 50 to 54.1 °C and 55 to 65 °Brix. Two reconditioning (RC) methods for the syrup used in the OPD of the peach slices were also evaluated: (1) by sieving, vacuum concentration and replacement of the syrup; (2) idem plus a filtration operation. The trials consisted of 15 OPD cycles (50 °C, 65 °Brix, syrup: fruit ratio of 4: 1) with RC and reuse (RU), followed by complementary drying (CD) (65 °C; 5 h). Physical, chemical and microbiological analyses were carried out on the syrups, raw material and dried fruit. The parameters WL and solids incorporation (SI) were determined and a sensory evaluation of the products was carried out. The microbial loads remained low and RC/RU had no influence on the parameters of WL and SI, nor on the sensory flavor or texture. RC/RU favored maintenance of the yellow color of the product and the methods showed similar performances. In sequence, the sensory performance of peach preserves prepared with the syrups from the previous step after 15 cycles of OPD with RC/RU was evaluated. Three syrup formulations were used for the preserves: (A) syrup from method (1); (B) syrup from method (2); and (C) freshly prepared syrup. There were no significant (p<0.05) differences between the treatments with respect to cloudiness of the syrup and fruit color, but with respect to flavor, treatments A and C were significantly (p<0.05) superior to B. Finally, the economic feasibility of a dried peach and pineapple producing unit (1300 kg fruit / day) using the combined OPD/CD process with syrup RC/RU (method 1) for 15 cycles, was evaluated. The initial investment, turnover capital, costs and total income were determined. Profitability was evaluated by analyzing the cash flow and ignoring third party capital. The return of investment (ROI) was 34% and the net present value (NPV) obtained indicated duplication of the capital in 20 years. These results indicated the economic feasibility of the project

ASSUNTO(S)

peach xarope osmotic dehydration fruit dehidration pessego pessego - secagem peach syrup desidratação osmotica frutas - desidratação

ACESSO AO ARTIGO

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