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The amino acid composition and the physicochemical and functional properties of quinoa flour proteins (QFP) were evaluated during storage (at 20, 30 and 40 °C). Quinoa flour showed a protein content of 14.2 ± 0.1 g 100 g−1 and high levels of essential amino acids as lysine. SDS–PAGE of the QFP presented ten major band, and native-PAGE of the QFP showed similar banding; there was a little variation due to time-temperature. TCA-protein solubility variation (%) was small and the values of water activity were low, a non-significant endogenous hydrolysis was observed. Differential scanning calorimetry flour analysis allowed determining two endotherms, starch and protein. Important structural changes of protein soluble fractions were not detected by UV and fluorescence spectroscopy due to temperature and time of storage. It was found during storage time loss of protein solubility and water absorption. These changes could be to influence in the manufacture of quinoa flour based products. For avoid changes in these functional properties (solubility and water holding capacity), quinoa flour can be stored at ambient temperature (between 20 and 30 °C) and packed in double kraft paper bags (2 months). [ABSTRACT FROM AUTHOR]

Summary: The present study aims to assess the seasonal and sex‐wise variations in proximate composition, amino acid profile and protein quality of Odonus niger, which will be the first report for this species. High‐protein (15.15%–20.05%) and low‐fat contents (0.46%–1.94%) were observed for the species studied. The highest protein was observed in September and December for male and female fishes respectively. The total essential amino acid (TEAA) content was 58.65–77.41 mg g−1 (males) and 60.25–77.38 mg g−1 (females) and leucine was the predominant EAA in both the sexes. The EAA index and biological value ranged between 17.50–22.56 and 7.38–12.89 for males and 18.02–22.48 and 7.94–12.80 for female fishes respectively. In male, TEAA followed Sept>Jan > Dec > Aug > Oct > Nov and in female it was Oct > Sept>Dec > Nov > Aug > Jan. The chemical score for histidine and threonine was more than the FAO recommended values. Overall, the nutritional quality of this unconventional species proved very good and comparable with other commercially important lean fishes. [ABSTRACT FROM AUTHOR]

Summary: Linoleic acid has been shown as a very important precursor for meat flavour and heating parameters may affect the reaction of linoleic acid with free amino acids (FAAs) or myofibrillar proteins (MPs) and the production of volatile organic compounds (VOCs). This study was aimed to identify the VOCs during heating of linoleic acid only or with FAAs and MPs for different times by gas chromatography‐ion mobility spectrometry (GC‐IMS). Reaction systems were set up to simulate meat, and the transformation pathway of VOCs was tracked by GC‐IMS. Finally, sixty‐two VOCs were identified, of which the content of aldehydes, which had the greatest impact on the aroma of meat, reached the peak (15.94%) when heated to 60 min and then decreased. Principal component analysis (PCA) showed that the effect of heating temperature on the flavour of the system was much greater than that of heating time, and heating at 90 °C for 60 min might be considered to obtain the best flavour. The results showed that FAAs played a critical role in the formation of VOCs that were derived from the oxidation and thermal degradation of linoleic acid, controlling the composition of FAAs may further optimise the flavour of processed meat products. [ABSTRACT FROM AUTHOR]

Summary: The aim of this study was to develop a green ultrasound‐assisted enzymatic process to separate protein from brewer's spent grain (BSG) to produce protein hydrolysates and determine the physicochemical properties of produced protein hydrolysates. When the enzyme (Alcalase) loading increased from 1 to 20 μL g−1 BSG, the protein separation efficiency increased from 34.0% to 61.6%. The application of ultrasound pretreatment further increased protein separation efficiency to 69.8%. More promisingly, the ultrasound pretreatment was able to reduce enzyme loading by 73% and decrease enzyme incubation time by 56%. The produced protein hydrolysates had molecular weights lower than 15 kDa and high protein solubilities at the pH of 1.0–11.0. The ultrasound pretreatment improved the protein solubility to above 90%. Glutamic acid and proline were the most abundant amino acids in produced protein hydrolysates. This study demonstrated that enzymatic hydrolysis along with ultrasound pretreatment is an effective way to separate protein from BSG. [ABSTRACT FROM AUTHOR]

The natural decomposition of proteins yields peptides and amino acids, which are susceptible to further decay, resulting in formation of biogenic amines ( BAs) in proteinaceous foods such as bee pollen ( BP). However, excessive consumption of BAs will bring side effects, so it is vital to study the presence of BAs in BP. In this study, a sensitive and reliable ultra -high-performance liquid chromatography-tandem mass spectrometric method was used for the determination of 12 BAs in BP. Large variations in the distribution and levels of BAs were observed with its total concentrations ranging from 6837.4 to 25444.2 μg kg−1. In addition, the changes in the levels of BAs during storage and fermentation were preliminarily investigated. The results showed that fermentation significantly altered the quantities of BAs in rape BP, while changes during storage were modest. The results of this study could be applied for quality evaluation and risk assessment of BP in near future. [ABSTRACT FROM AUTHOR]

Maize like other cereals shows qualitative and quantitative deficiency in protein content. Efforts were made to correct this by fortification, supplementation and fermentation. Two maize cultivars, Hudeiba 1 and Mugtama 45, were used to study the effect of fermentation followed by cooking on their protein quality. Maize flour was fermented for 32 h; samples were withdrawn at 8 h intervals. Results indicated that the proteins fractions albumins plus globulins were significantly ( P < 0.05) increased in the fermented doughs. This is an indication of improvement in the protein quality of maize. Cooking resulted in significant ( P < 0.05) changes in protein solubility. The essential amino acids particularly lysine increased from 1.82 to 2.06 and from 1.88 to 2.60 g/100 g (i.e. an increase of 11.6% and 27.7%) for Hudeiba 1 and Mugtama 45, respectively. The in vitro protein digestibility of cooked samples decreased significantly ( P < 0.05); however, the negative effects of cooking were lower than those of unfermented cooked samples. [ABSTRACT FROM AUTHOR]

Sicklepod leaves after fermentation and drying are commonly known as Kawal in Sudan. Investigation of the samples showed that the dry matter, oil, fibre and carbohydrates fluctuated during processing. The protein content of Algenina increased to 30.01% while that of Zalngy decreased to 24.32%. Cooking increased the ash content to 19.55% and 20.04% for Algenina and Zalngy samples respectively. For both samples the total energy was decreased to 221.59 and 227.39 kcal per 100 g for the samples respectively. The first limiting amino acid is lysine with a score of 73.9. Although cooking of the sample increased lysine score to 76.00 but still is a limiting amino acid. Sulphur amino acids are the second limiting of Zalngy. The protein fractions fluctuated during processing. Cooking of the samples decreased polyphenols to 890.01 and 620.58 mg per 100 g and phytate to 77.90 and 146.28 mg per 100 g for the samples respectively. However, tannin content increased to 1183.65 and 977.65 mg per 100 g for the samples respectively. For Algenina sample the protein digestibility increased to 50% after cooking but for Zalngy it decreased to 30%. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the effects of industrial processing on the composition of proteins, free amino acids and phenolics in Castanea sativa Mill. fruits of 2 years. The Portuguese cultivars were Judia, Longal, Martaínha and Lada, and the European cultivars were ‘Spanish’ (Puga do Bolo) and ‘Italian’ (Viterbes). At all processing stages the fruits contained low contents of protein (4.1–5.4 g 100 g−1 d.m.). The essential amino acid Thr had the highest values (3.6–10.0 mg 100 g−1 f.w.), while the highest non-essential amino acid was Asn (14.9–36.4 g 100 g−1 f.w.). Total phenolics (6.6–18.3 mg g−1 f.w.) were more significantly affected by the processing stage factor. In 2007 the gallic acid contents were more affected by the processing stage and interaction factors (cultivar × processing stage), whereas the cultivar factor had more of an effect on ellagic acid. Industrial processing has some negative effects, specifically reducing the contents of some amino acids. [ABSTRACT FROM AUTHOR]

The legumes Canavalia ensiformis and Mucuna pruriens are underexploited in tropical Mexico. Their seeds have good nutritional potential, but contain antinutritional factors. Physicochemical and antinutritional properties were determined for raw flours (RF) and protein isolates (PI) produced from these legumes. Protein content in the PI was 737 g kg–1 for C. ensiformis and 666 g kg–1 for M. pruriens. Protein isolation improved in vitro digestibility, while maintaining high lysine levels and adequate sulphur amino acids content. Antinutritional factors such as cyanogenic glucosides, cyanide precursors from hydrolysis, tannins and trypsin inhibitors were lower in the PIs than in the RFs. The reduction in canavanine levels, a structural analogue of arginine, in the C. ensiformis PI was noteworthy. These PIs thus have potential applications in the development of new food ingredients in tropical regions using processes that improve nutritional value. [ABSTRACT FROM AUTHOR]