Optimization of a novel, gluten-free bread's formulation based on chickpea, carob and rice flours using response surface design.

This study aimed to develop nutritious, gluten-free bread with high quality characteristics using a mixture of chickpea, carob and rice flours as substitutes of wheat flour. To optimize the bread formulation, a Box-Behnken experimental design was conducted to evaluate the effect of the corresponding flour blend addition, proofing time and water amount addition on the physicochemical, technological and sensory properties of the obtained formulated bread. The optimized formulation was calculated to contain 70% of mixture flour and 100% of water, with a proofing time of 40 minutes. This formulation produced bread with greater specific volume ( 3.73 ± 0.37 cm3/g) and less baking loss ( 22.98 ± 0.94 % ) than those of control (+) bread ( 2.93 ± 0.21 cm3/g and 31.65 ± 0.72 % , respectively). Findings proved that the mixture flour based on chickpeas, carob and rice represents a good alternative to make gluten-free bread with acceptable baking properties.

Characterization of nettle leaves (Urtica dioica) as a novel source of protease for clotting dromedary milk by non-destructive methods.

This study investigates the valorization of the nettle leaves (Urtica dioica) as a novel source of a protease for clotting dromedary milk. The aim of this work is to study the effect of extracting pH on the enzymatic activity of nettle leaves extracts. The extraction was achieved in phosphate citrate buffer at different pH values (from 3 to 6.5) and the obtained extracts were used to coagulate dromedary milk. The characterization of the obtained extracts was carried out using non-destructive methods namely FT-MIR, fluorescence spectroscopy and turbiscan instrument. The extract prepared at pH = 4 had the highest proteolytic activity. The fluorescence and turbiscan measurements revealed a substantial effect of the pH value on chlorophyll residues extraction and stability, respectively. At an acidic environment (pH range of 3 - 4), the enzymatic extracts were unstable (with turbiscan stability index (TSI) values ~ 20), while at a nearly neutral pH value (pH range of 5 - 6.5), they were found to be more stable as indicated by the low TSI values ~ 1. The maximum milk-clotting activity (MCA) (0.021 U/mL) was obtained for the extracts prepared at pH = 4.

Optimization of gluten-free sponge cake fortified with whey protein concentrate using mixture design methodology.

This study aimed to optimize mixtures of whey protein concentrate (WPC) and two flours of rice and maize flours for the production of gluten-free sponge cakes. This was obtained by using mixture design methodology. WPC incorporation had positive effects on specific volume and baking loss of cakes, whilst, their incorporation increased their hardness. Considering all cakes properties, two formulas F1 (78.5% Maize, 15% Rice and 6.5% WPC) and F2 (82.4% Maize, 12% Rice and 5.6% WPC) were optimized using a mixture design. The microstructure F1 was more organized and very well structured with smaller aggregates. According to the organoleptic evaluation, F1 was also most appreciated by the tasting panel. The findings of the present study indicated that maize and rice flours, and WPC could be used as a substitute for wheat flour in producing sponge cakes of high quality.

Proteomic profiling of camel and cow milk proteins under heat treatment.

Cow and camel milk proteins before and after heat treatment at 80°C for 60min were identified using LC/MS and LC-MS/MS following monodimensional electrophoresis. The database used for the identification of camel and cow proteins was set from http://www.uniprot.org/. The obtained results showed that, after heating, camel milk at 80°C for 60min, camel α-lactalbumin (α-la) and peptidoglycan recognition protein (PGRP) were not detected while camel serum albumin (CSA) was significantly diminished. When heating cow milk at 80°C for 60min, α-lactalbumin (α-la) and ß-lactoglobulin (ß-lg) were not significantly detected. Moreover, 19 protein bands from SDS-PAGE were analyzed and a total of 45 different proteins were identified by LC-MS/MS. Casein fractions were kept intact under a heat treatment of 80°C during 60min of both camel and cow milks. Camel and bovine whey proteins were affected by a heat treatment of 80°C for 60min.

Low-fat Gouda cheese made from bovine milk-olive oil emulsion: physicochemical and sensory attributes.

The objective of this paper is to study the effect of milk-fat replacement on Gouda cheeses composition, lipolysis and sensory characteristics. A Gouda cheese-like product was prepared from the substitution of milk fat with emulsified olive oil. For comparison, the low-fat variant without fat replacers and the full-fat cheese were also studied. Milk samples are initially pasteurized at 72 °C for 3 s, cooled to 35 °C, and added with 0.016 g L(-1) of lactic ferments and 0.30 mL L(-1) of microbial rennet. Total solids content was lower in cheeses containing fat replacers than in full and low-fat control cheeses due to the higher water-binding capacity of fat replacers. Free fatty acids rates were the highest in the case of reduced fat cheese-like product. The full-fat cheese showed a significantly higher overall impression score than all low-fat products.