A desidratação osmótica é um processo que pode ser aplicado a frutos, para aumentar sua vida útil e, conseqüentemente, reduzir o percentual de perdas. Na aplicação deste processo em jenipapo, foi observada uma elevada incorporação de sólidos solúveis, considerada desvantajosa por reduzir a similaridade entre o produto e o fruto "in natura". Neste trabalho, foram empregados revestimentos comestíveis à base de alginato e pectina de baixa metoxilação, com o objetivo de diminuir a transferência de massa, cuja eficácia foi avaliada em jenipapos adquiridos nos supermercados da Região metropolitana do Recife, nas condições em que são comercializados. A pesquisa foi desenvolvida em duas etapas. A primeira, por meio de planejamento fatorial fracionário 2(3-1), com o objetivo de estudar a influência das coberturas, constituída por três tratamentos: A (frutos sem revestimento); B (frutos cobertos com alginato); e C (frutos cobertos com pectina. A segunda, por planejamento fatorial 2³, para determinar a influência das variáveis independentes, temperatura, tipo de cobertura e geometria sobre a perda de umidade, ganho de solutos, variação de peso e taxa de DEI (Dehydration Efficiency Index). Os resultados obtidos na 1ª etapa evidenciaram que: as coberturas foram eficientes na redução da incorporação de solutos, bem como no aumento de perda de umidade; os maiores DEI, em ambas as coberturas, foram obtidos a 50 °Brix, sendo o máximo a 30 °C e geometria representada por um quarto de fruta. Na 2ª etapa, foram confirmados maior influência da geometria sobre a perda de umidade e o ganho de solutos e das coberturas sobre a variação de peso e perda de umidade. Foi constatado que a temperatura exerce decisiva influência sobre as demais variáveis, com exceção dos DEI. Os resultados permitiram concluir que os menores ganhos de solutos, associados a uma satisfatória perda de umidade, foram obtidos com cobertura de alginato, geometria representada por um quarto de fruta, a 50 °Brix, independente das temperaturas, permitindo fixá-las em 50 °C.

Osmotic dehydration is a process that can be applied to fruit to increase their shelf life and hence reduce loss percentage. In the application of this process in jenipapo, a high incorporation of soluble solids was observed, considered disadvantageous because of the reduction of the similarity between the product and the fruit "in natura". In this work, low metoxilation alginate and pectin based edible coating were used to reduce this mass transfer. The effectiveness of these polysaccharides was evaluated in Jenipapos, purchased in supermarkets in the metropolitan area of the city of Recife, in the conditions in which they are sold. The research was developed in two stages: the first by means of a factorial design 2(3-1), consisting of three treatments: A (fruits without coating); B (fruits with alginate coating); and C (fruits with pectin coating) in order to study the influence of the coatings; in the second stage a factorial design 2³ was used in order to determine the influence of independent variables: temperature, coating type and geometry over moisture loss, solutes uptake, weight variation and rate of DEI (Dehydration Efficiency Index). The results obtained in the first stage showed that: the coatings were efficient in the reduction of solutes uptake as well as in the moisture loss increase, the higher DEI in both coatings were obtained at 50 °Brix, the highest DEI at 30 °C and the geometry was represented by the fruit cut in fourths. In the second stage a higher influence of the geometry over the moisture loss and the solute uptake as well as the coatings over the weight variation and moisture loss were confirmed. It was observed that the temperature exerts decisive influence over the other variables with the exception of the DEI. The results showed that the lower solutes uptake associated with a satisfactory moisture loss were obtained with alginate coating and the geometry was represented by the fruit cut in fourths, at 50 °Brix, regardless of the temperatures, allowing to set it at 50 °C.

Microbiological processes were used for chitin and chitosan productions by Cunninghamella elegans (UCP 542) grown in a new economic culture medium. The assay was carried out to evaluate the growth of C. elegans using yam bean (Pachyrhizus erosus L. Urban) medium, in different times of growth (24, 48, 72 and 96 hrs), incubated at 28ºC in an orbital shaker at 150 rpm. The lyophilized biomass was determined by gravimetry. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, titration and viscosity. C. elegans grown in the yam bean medium and produced higher yields of biomass (24.3 g/ mL) in 96 hrs. The high level was chitosan (66 mg/g), and chitin (440 mg/g) were produced at 48 and 72 hrs of growth, respectively. The polysaccharides showed degree of deacetilation and viscosimetric molecular weight as: 6.2% and 3.25 x10(4) g/mol for chitin, and 85% and 2.72 x 10(4) g/mol for chitosan, respectively. The results obtained suggest high biotechnological potential of yam bean as an economic source to produce chitin and chitosan by C. elegans. In addition, the new medium using yam bean for production of the chitin and chitosan may be used for many purposes to reduce the cost price of fermentation processes.