High Throughput Screening for Bioactive Volatile Compounds and Polyphenols from Almond ( Prunus amygdalus ) Gum: Assessment of Their Antioxidant and Antibacterial Activities

International audienceThis work was devoted to recover and identify bioactive polyphenols and volatile compounds from almond gum, which can be used as food additives and/or nutraceuticals. For this purpose, solvent extract was obtained after hydrodistillation of almond gum and the extracted volatiles were identified using gas chromatography‐mass spectrometry (GC‐MS). The major compounds were 9‐octadecenoic acid (18.47%), 3‐eicosene (17.04%), hexadecanoic acid (13.82%), benzyl salycilate (9.54%), 1‐octadecene (7.28%), cetene (4.38%) and turmerone (3.2%). Subsequently, the antioxidant and antibacterial activities of the obtained extracts rich in polyphenols and volatile compounds were evaluated. Antioxidant activities showed 90.2% DPPH free radical inhibition and 206.8 µg ascorbic acid equivalents/mL using 50 mg/mL solvent extract, whereas the reducing capacity at 700 nm and 30 mg/mL was 0.8 ± 0.09. In addition, the antibacterial activities against 10 pathogenic strains were studied, showing the maximum growth inhibition, when using 50 mg solvent extract, against Enterobacter spp., Salmonella typhimurium, Listeria monocytogenes, Micrococcus luteus and Bacillus subtilis with diameter of inhibition zones of 30.4 ± 0.5, 19 ± 1.3, 27.5 ± 1.2, 28.2 ± 1.0 and 25.5 ± 0.3 mm, respectively

Effects of almond gum as texture and sensory quality improver in wheat bread

International audienceThe aim of this work was to investigate the effect of almond gum as dietary fibre source in enhancing the wheat bread quality. Different amounts of almond gum (2%, 5% and 10% (w/w)) were used in bread formulation. The volume, texture, crust and crumb colour, as well as the sensorial properties, were evaluated and compared to control (without almond gum). The obtained results showed that almond gum addition enhanced significantly the volume of bread. The highest volume was obtained using 2% almond gum concentration with 23.6% increase, compared to control. Using almond gum in bread formulation improved considerably its texture with a notable decrease in hardness by 61.7% and 42.5% when using 2% and 5% almond gum, respectively. The sensory analysis scores showed that the better overall acceptability was found for breads supplemented with 2% almond gum, as compared to control and breads supplemented with 5% or 10% almond gum

Water-soluble polysaccharides and hemicelluloses from almond gum: Functional and prebiotic properties

International audienceThis paper describes the extraction of polysaccharides (AGP) and hemicelluloses (AGH) from almond gum by hot water and alkaline solution, respectively. Structural and functional properties of the extracted polymers were then determined. For this purpose, infrared spectroscopy was first used to characterize functional groups of both polymers. The molecular weights of AGP and AGH were then determined using high performance size exclusion chromatography, resulting in 5.72×106g/mol and 5.39×106g/mol, respectively. Monosaccharide composition of both polymers was assessed using gas chromatography. The analysis of the functional properties showed that AGP and AGH had high water-holding (11.36g/g and 6.3g/g, respectively) and fat-binding (5.35g/g and 2.7g/g, respectively) capacities, with good emulsion properties. The prebiotic properties of AGP and AGH were then evaluated using in vitro fermentation by Bifidobacterium adolescentis and Lactobacillus acidophilus. Both polymers showed suitability for in vitro fermentation, suggesting thus their prebiotic nature. The obtained results demonstrated the promising potential of AGP and AGH for different applications in food industry