Technological properties of pre-gelatinized rice flour obtained by thermoplastic extrusion

The rice flour has become an attractive ingredient in the extrusion industry due to its unique attributes such as bland taste, white color and hypoallergenicity. The purpose of this research was to produce and analyze pre-gelatinized rice flour (GRF) for thermoplastic extrusion. The GRY was extruded using a Brabender single screw extruder, varying moisture (19.2 - 24.8%) and extrusion temperature (108 - 192 degrees C). Torque, expansion index (EI), viscographic properties, water absorption index (WAI), and water solubility index (WSI) characteristics of GRF were analyzed using response surface methodology (RSM) and main component analysis (PCA). The results, analyzed by MRS and PCA, indicated that during the process, the values of torque and El increased when lower moisture was used. Considering viscographic properties, GRF presented a higher initial viscosity of the starch paste when in higher temperatures, while viscosities at 95 degrees C and at 50 degrees C increased when temperature and moisture were at extreme opposites. WAI decreased when lower temperatures and higher moisture were used. WSI was not influenced by temperature and moisture when analyzed using MRS, but with PCA, there was an increase when temperatures ranged between 120 - 150 degrees C and moisture between 19.2 - 22%. In conclusion, both MRS and PCA analysis showed that a variation in the technological properties of GRF were related to the use of opposite extremes of temperature and/or moisture during the extrusion process, and the PCA was able to complete the analysis done using MRS.3251543155

Extruded rice flour as a gluten substitute in the poduction of rice bread.

Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pre-gelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192 degrees C) and the moisture of the raw material (19.2-24.8%), and were used in a proportion of 10g for every 100g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.56328829

Production of acidic extruded rice flour and its influence on the qualities of gluten-free bread

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)One of the greatest technological challenges in the production of gluten-free bread (GFB) is to find a low-cost ingredient capable of retaining gas during fermentation and the baking process. The use of gelatinized starch appears to show promise for this purpose. In this study, GFB was made using raw rice flour (100 g) with the addition of 10 g acidic extruded rice flour (AERF). The AERF was produced in a single-screw extruder, varying the extrusion temperature and lactic acid concentration. Response surface methodology (RSM) and the principle components analysis (PCA) were used to analyze the results. The results of RSM showed no significant difference, but the mean volume obtained with the AERF (1.95 mL g (-1)) was still low when compared with that of wheat bread (6 mL g(-1)). The crust and crumb colors and the texture (hardness = 173 g; chewiness 90.5 and fracturability = 178) presented results similar to those of wheat bread and better than other GFB found in the literature. When analyzed by PCA the AERF obtained at 150 degrees C-0.5 mol L(-1) lactic acid, showed the best results for the GFB obtained. IR spectroscopy showed that no bands were found for esters (1740 cm(-1)) in the AERFs, which could indicate that no new bonds were formed between the rice flour and the lactic acid. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.422618623Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Production of acidic extruded rice flour and its influence on the qualities of gluten-free bread

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)One of the greatest technological challenges in the production of gluten-free bread (GFB) is to find a low-cost ingredient capable of retaining gas during fermentation and the baking process. The use of gelatinized starch appears to show promise for this purpose. In this study, GFB was made using raw rice flour (100 g) with the addition of 10 g acidic extruded rice flour (AERF). The AERF was produced in a single-screw extruder, varying the extrusion temperature and lactic acid concentration. Response surface methodology (RSM) and the principle components analysis (PCA) were used to analyze the results. The results of RSM showed no significant difference, but the mean volume obtained with the AERF (1.95 mL g (-1)) was still low when compared with that of wheat bread (6 mL g(-1)). The crust and crumb colors and the texture (hardness = 173 g; chewiness 90.5 and fracturability = 178) presented results similar to those of wheat bread and better than other GFB found in the literature. When analyzed by PCA the AERF obtained at 150 degrees C-0.5 mol L(-1) lactic acid, showed the best results for the GFB obtained. IR spectroscopy showed that no bands were found for esters (1740 cm(-1)) in the AERFs, which could indicate that no new bonds were formed between the rice flour and the lactic acid. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.422618623Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Interaction of Guar and Xanthan Gums with Starch in the Gels Obtained from Normal, Waxy and High-amylose Corn Starches

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The objectives of the present study were to analyze the chemical interactions between guar and xanthan gums and starches. Gels were obtained from normal (NCS), waxy (WCS) and high-amylose (HACS) corn starches containing gums. The gels were evaluated according to their pasting properties and infra-red absorption. The guar (GG) and xanthan (XG) gums affected the properties of the NCS paste more significantly than those of the WCS paste. In the infra-red absorption spectra, no covalent bonds between the starches and gums were observed under the conditions studied, so probably the only interactions occurring between them were hydrogen bonds.6112834Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAEPEXConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaluation of the in vitro glycemic index of a fiber-rich extruded breakfast cereal produced with organic passion fruit fiber and corn flour

The aim of this study was to determine the influence of process parameters and Passion Fruit Fiber (PFF) addition on the Glycemic Index (GI) of an extruded breakfast cereal. A 2(3) Central Composite Rotational Design (CCRD) was used, with the following independent variables: raw material moisture content (18-28%), 2(nd) and 3(rd) barrel zone temperatures (120-160 degrees C), and PFF (0-30%). Raw materials (organic corn flour and organic PFF) were characterized as to their proximate composition, particle size, and in vitro GI. The extrudates were characterized as to their in vitro GI. The Response Surface Methodology (RSM) and Principal Component Analysis (PCA) were used to analyze the results. Corn flour and PFF presented 8.55 and 7.63% protein, 2.61 and 0.60% fat, 0.52 and 6.17% ash, 78.77 and 78.86% carbohydrates (3 and 64% total dietary fiber), respectively. The corn flour particle size distribution was homogeneous, while PFF presented a heterogeneous particle size distribution. Corn flour and PFF presented values of GI of 48 and 45, respectively. When using RSM, no effect of the variables was observed in the GI of the extrudates (average value of 48.41), but PCA showed that the GI tended to be lower when processing at lower temperatures ( 158 degrees C). When compared to white bread, the extrudates showed a reduction of the GI of up to 50%, and could be considered an interesting alternative in weight and glycemia control diets.30496496

Evaluation of dehydrated marolo (Annona crassiflora) flour and carpels by freeze-drying and convective hot-air drying

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Marolo (Annona crassiflora), an exotic fruit from the Brazilian savanna, has been used for many culinary preparations such as jelly and jam. In this study we have compared physicochemical properties, color analysis, dietary fiber and triacylglycerol analysis of marolo flour and carpels dehydrated by freeze-drying and convective hot-air drying. The experiments were analyzed by Tukey's test (p < 0.05). There was a significant difference between fresh and dehydrated marolo as shown by the analysis of moisture, Aw, and the centesimal composition (except for the ashes). The dehydrated products showed to be sources of alimentary fiber and derivatives from oleic and palmitic acids and can be used during periods between harvests of marolo fruits. (c) 2011 Elsevier Ltd. All rights reserved.447SI23852390Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FINEPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPEMIG (CAG) [CAG - APQ-02130-08

Physical, chemical and technological characteristics of Solanum lycocarpum A. St. - HILL (Solanaceae) fruit flour and starch

Fruit of wolf (Solanum lycocarpum A. St. - HILL), found in Brazilian cerrado, has been used in the initial ripening stage as flour and/or starch in popular medicine due to its hypoglycemiant action. The aim of this work was to study the occurrence of phytochemical compounds, physical, chemical and technological characteristics of fruit of wolf flour and starch in the initial ripening stage. Flour and starch were extracted using known popularly and experimental methods (with sodium bisulfite) and chemical composition and technological characteristics were analyzed. The results were comparatively assessed by Tukey's test (p<0.05). The recommendation for use was the extraction of flour and starch products by previously removing peels and seeds of fruit of wolf. The most relevant finding in this study is the high content of fibers in flour (23 g/100 g) and high content of resistant starch (32 g/100 g) in the fraction of starch extracted from fruit of wolf, which can explain their use as hypoglycemic agent. (C) 2011 Elsevier Ltd. All rights reserved.447SI2143215