Thermorheological and textural behaviour of gluten-free gels obtained from chestnut and rice flours

Nowadays, as celiac disease is becoming more common the consumers’ demand for gluten-free products with high nutritional and taste quality is increasing. This work deals with the study of the impact of four novelty gluten-free sources: chestnut flour (Cf), whole rice flour (Rw), Carolino rice flour (Rc) and Agulha rice flour (Ra). Textural, thermorheological and stability performance of gluten-free gels using different experimental techniques were evaluated. Mixed gels were also produced for comparison. Texture parameters were determined from the texture profile analysis using a texturometer. Thermorheological oscillatory measurements were conducted in a stresscontrolled rheometer in order to clarify the kinetics of gel formation and to characterise the structure of the matured gels. The stability of the gels was evaluated using transmittance profiling of the gels under gravitational fields (LUMiSizer®). Texture studies suggested that gels from mixtures of chestnut flour at 30 % and rice flour at 20 % showed the right texture to develop gel-based new desserts. Rheological results showed that the thermal profiles on heating of Cf gels were similar to those obtained for Rw and Ra, whereas Rc gels exhibited a particular pattern. Once the final gelatinisation temperature was achieved, no significant differences on the viscoelastic properties were noticed for all the tested gels. Stability tests showed that gels with Rc should present an industrial advantage over the other assayed formulations, since the stability of these gels is of the order of four times larger

Study of the proximate and mineral composition of different Nigerian yam chips, flakes and flours

Yam (Discorea spp.) is an essential tuber crop for the hundreds of millions of people in many African, Asian and South American countries; considering in particular Southwest Nigeria, chips, flakes and flours are between the most common shelf-stable traditionally processed yam products. This paper reports a systematic study on the proximate (moisture, protein, carbohydrate, fibre, fat, ash and gross energy) and mineral composition of these three food commodities sold in Nigerian markets. Results showed no significant differences (p>0.05) in the moisture, crude protein and fibre content of all samples. Gross energy was also comparable for all yam derived food items, contradicting the common belief that yam flakes have lower nutritional value. As for the mineral composition, Ca, Mg, P and K were the predominant macronutrients. Micronutrients such as Zn, Co, Mn and Cu were also detected. Significant differences (p<0.05) existed between samples and various markets of source. Principal component analysis (PCA) showed a direct correlation between the ash content of the samples and the macronutrients assessed, irrespective of the market or seller of the commodities. This study confirmed that yam derived food stuff have an adequate nutritional composition, irrespective of their form and/or origin

Hydrolysis of starches and flours by sorghum malt amylases for dextrins production

peer reviewedCorn and wheat starches as well as wheat and cassava flours were hydrolyzed using sorghum malt at 65 °C for 6 hours. During these reactions, dextrose equivalent (DE) values were followed under 3 concentrations of sorghum malt and of calcium chloride. Wheat flour presented the highest DE values and cassava flour had the highest hydrolysis yield. Thus, different dextrins were produced in a pilot plant and were analyzed by HPSEC and HPAEC-PAD for their molecular weight distribution and oligosaccharides composition respectively. The results indicated that oligosaccharides with broad molecular weight distributions were present in the dextrins produced and that the proportion of maltose was very high