Silene Bruder Silveira Sarmento

New starches for the food industry: Curcuma longa and Curcuma zedoaria

Univ Estadual Paulista Julio Mesquita Filho, CERAT, Ctr Raizes & Amidos Trop, Botucatu, SP, Brazil

Conservação de maçã minimamente processada com o uso de películas comestíveis

The effect of edible coatings on the preservation of the Minimally Processed (MP) Royal Gala apples under refrigerated storage for 13 days was studied. The treatments were: the control solution, preserving solution (1% of acid ascorbic; 0,5% of citric acid; 0,7% of NaCl; 0,25% of CaCl 2 ), manioc starch (3%), and sodium alginate (2%) with CaCl 2 . The preserving solution decreased the respiratory and the ethylene production rate and showed a lighter pulp. The coatings decreased the respiratory rate by 38% and the ethylene production by 50%. The alginate was the most efficient, and it presented a better retention of moisture up to the 9th day of storage. The control presented less firmness at during storage, but the other treatments presented the opposite. Apples with alginate presented less acidity and a darker coloration because of the pH and the coloration of the filmogenic solution.

Efeito dos parâmetros de extrusão sobre as propriedades funcionais de extrusados da farinha de batata-doce

ae 2a zonas de extrusao (20oC e 60oC, respectivamente). O efeito das variaveis umidade da farinha (15, 18 e 21%), temperatura na 3a zona (100, 120 e 140 o C) e rotacao da rosca (180, 210 e 240 rpm) sobre as caracteristicas dos extrusados foi investigado utilizando-se metodologia de superficie de resposta. O teor de umidade e a temperatura de extrusao influenciaram significativamente a expansao dos extrusados. O indice de expansao apresentou valores crescentes com a temperatura sob baixos teores de umidade. A dureza dos extrusados e tambem o indice de absorcao de agua e o indice de solubilidade em agua das farinhas extrusadas nao mostraram modelo de regressao significativo com as condicoes de processo. Quanto a cor das farinhas, o componente L* (luminosidade) apresentou valores crescentes e o parâmetro a*, valores decrescentes com a elevacao do teor de umidade ate 20-21%. O parâmetro b* e a diferenca de cor entre farinhas extrusadas e nao extrusadas mostraram valores decrescentes com o aumento da umidade. Palavras-chave: batata-doce, extrusados, indice de expansao, indice de absorcao de agua, indice de solubilidade em agua. SUMMARY EFFECT OF EXTRUSION PARAMETERS ON SWEET POTATO EXTRUDATES. Sweet potato flour was processed using a single-screw extruder, with extrusion temperatures in zones 1 and 2 of 20 o C and 60 o C, respectively. The effect of flour moisture content (15, 18 and 21%), barrel temperature in zone 3 (100, 120 and 140 o C) and screw speed (180, 210 and 240 rpm) on extrudate attributes was investigated using response surface methodology. Moisture content and extrusion temperature had a significant (p<0.05) influence on extrudates expansion. The expansion ratio of the extrudates showed increasing values with temperature under conditions of low moisture content. The firmness of extrudates and also the water absorption index and water solubility index of the pre-gelatinized flours did not show significant regression models with the processing conditions. The flours color was influenced by the moisture content. The component L* showed increasing values and the parameter a* exhibited decreasing values with the increase of moisture content till 20-21%. The parameter b* and the difference of color between extrudated and non extrudated flours showed increasing

Extração e caracterização de amido de jacatupé (Pachyrhizus ahipa)

The species of the genus Pachyrhizus have been studied as a potential starchy raw material source. This work had as purpose the characterization of P. ahipa roots and process the roots in laboratory for starch extraction. The centesimal composition and amylose content of starch were analyzed. The starch granule size and shape were observed in scanning electronic microscopy. The Rapid Visco Analyzer was used for viscosity analysis. The P. ahipa roots showed high humidity (82%) and 7,68% of starch. The process yield was low (4.28%), which reveal the necessity of searches for improving starch extraction. The product showed 12.3% of humidity, 84% of starch (13% amylose) and low content of other components. The starch granules had circular and polygonal shapes; the size ranged between 10 and 25mm. The viscosity profile of the P. ahipa starch showed low pasting temperature (56oC), peak at 272 RVU, high breakdown value and a tendency to setback.

Propriedades de barreira e solubilidade de filmes de amido de ervilha associado com goma xantana e glicerol

The aim of this work was to evaluate the barrier properties and solubility of biofilms made from wrinkled pea starch with high amylose content in association with xanthan gum and glycerol. Filmogenic solution (FS) with different levels of pea starch (3, 4 and 5%), xanthan gum (0, 0.05 and 0.1%) and glycerol (glycerol-starch 1:5 W/W) were tested. FS was obtained by boiling (5 minutes), autoclaving for 1 hour at 120 oC and the films were prepared by casting. The increased concentration of starch and glycerol in the composition caused increases in thickness of the films and in their solubility in water. The plasticizer also generated higher coefficients of water vapor and oxygen permeabilities to water vapor and to oxygen. The increasing concentration of xanthan gum did not interfere in the properties studied. Biofilms produced with wrinkled pea starch, with or without xanthan gum and glycerol, showed better barrier to oxygen and water vapor and low solubility in water, in comparison with films of yellow pea starch and other starch sources.

Physicochemical and structural characteristics of rice starch modified by irradiation.

This work evaluated the physicochemical and structural properties of rice starch of the cultivars IAC 202 and IRGA 417 modified by irradiation. Starch samples were irradiated by (60)Co in doses 1, 2 and 5kGy, on a rate of 0.4kGy/h. A control not irradiated was used for comparison. The granule morphology and A-type X-ray diffraction pattern were not altered by irradiation. There was an increase in amylose content, carboxyl content and acidity with irradiation. Gamma radiation did not affect the thermal properties of IAC202, but increased gelatinization temperature of IRGA417, in the higher dose (5kGy). The number of long chains of amylopectin was reduced and short chains were increased for IAC202, whereas for IRGA 417, the opposite was observed, probably due to cross-linking of starch chains. Starches had their physicochemical and structural properties modified by irradiation differently.

Efeito da irradiação gama nas características físico-químicas e sensoriais do arroz (Oryza sativa L.) e no desenvolvimento de Sitophilus oryzae L.

The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L.) conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental), and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p < 0.05) was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b* indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best to meet the objectives of this study.

Efeito do cloreto de cálcio e da película de alginato de sódio na conservação de laranja 'Pera' minimamente processada

The aim of this study was to assess the effect of a calcium chloride solution and a film of sodium alginate on the conservation of minimally processed ‘Pera’ oranges. The quality of minimally processed orange submitted to treatments with 1% calcium chloride and 1% sodium alginate and the control (without treatment application) were monitored by physical, chemical, microbiological, and sensorial analyses every 3 days during storage at 5 °C for a period of 12 days. Treatment with sodium alginate (1%) showed loss of smaller mass over the period of storage; however, the quality of the samples subjected to this treatment was compromised regarding the contents of ascorbic acid, sugars, soluble solids, and firmness. At the end of the storage period, the treatment with calcium chloride (1%) showed the best performance in maintaining the initial characteristics of the fruit preserving the contents of ascorbic acid, acidity, ‘ratio’, sugars, and firmness evidenced by the lower pectin solubilization. The microbiological analysis found negligible values of psycrotrophic bacteria, yeasts, molds, and total coliforms in all treatments. This indicates that a control of hygienic conditions led to a standard microbiological product according to the food legislation without Salmonella and coliforms under 45 °C. Sensorially, minimally processed orange treated with calcium chloride (1%) and control proved good for consumption for up to nine days of storage.

Efeito de revestimentos comestíveis na conservação de mamões minimamente processados

Summary The experiment evaluated the effects of carbohydrate-based coatings on the microbiological, physical, physical-chemical and sensory properties of the fresh cut (FC) Formosa papaya stored under refrigeration. After treatment with calcium chloride, peeled and sliced portions of the fruit were immersed in 3.0% rice starch (RS), 0.5% sodium alginate (SA) and 0.25% carboxymethylcellulose (CMC) solutions, and stored at 5 °C and 90% RH. The products were assessed after 1, 3, 6, 9, 12 and 15 days of storage. The use of the RS, SA and CMC-based coatings for TC papaya resulted in lower total coliform counts than presented by the control sample. The papaya coated with RS and CMC showed decreased and increased respiration rates, respectively. The coated samples showed lower soluble solid contents, with decreased pH values after storage day 9, and the use of CMC as a coating resulted in increased pulp firmness on day 15. Variations in the colour parameters (Luminosity, Hue and Chroma) did not compromise the sensory quality of the TC papaya, and the sensory attributes of the coated samples did not differ from the control samples throughout the 15 days of experimentation. Since most of the positive results were shown on days 12 and 15, and considering the costs of this technology and price of the coatings, for periods of up to 9 days the best option consists of simply sanitizing the fruits, as done with the control samples. If aiming to preserve the shelf life of the papaya slices for a longer period of time (namely, up to 15 days), the above coatings may show satisfactory results so long as the storage conditions described here are accurately reproduced.

Planting time, developmental stages and characteristics of roots and starch of Pachyrhizus ahipa

Starch characteristics generally alter with plant developmental stage. The object of this study is to evaluate the effects of planting and harvesting dates on root physical-chemical characteristics, starch granule size distribution, and viscographics properties of starches in Pachryrhizus ahipa. Harvesting dates influenced root and starch characteristics for the two planting dates. The best conditions for cultivating Pachyrhizus ahipa for starch extraction are October planting and July harvesting dates. Their flowers must be cut after three months of cultivation.