Search

Summary: Alaska pollock (Gadus chalcogrammus) is a marine fish that lives in the North Pacific Ocean. G. chalcogrammus contains high nutritional value, especially protein. Alaska pollock proteins (APP) and its peptides have been reported to have biological activities. However, the biological activities of APP have not been reviewed so far. The aim of this study was to review the published research on APP and its peptides, as well as their potential biological activities, using the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. We used ScienceDirect, PubMed and Web of Science to identify the relevant references. In total, 43 studies were obtained and reviewed after the filtering process. Most of the research has focused on APP's prospective biological activities. The current study revealed that APP possesses biological activities, including skeletal muscle hypertrophy, anti‐obesity, anti‐cholesterol, blood glucose‐lowering and anti‐non‐alcoholic fatty liver effects. Peptides that are hydrolysed from APP possess biological activities, such as ACE inhibition, antioxidant effects, immunomodulation, anti‐diabetic, mineral chelation and wound healing activities. Only a few clinical studies were available on either APP or the respective peptides. Therefore, further study is needed to completely understand the potential of APP and the associated peptides as novel nutraceutical and functional food, as well as to evaluate their effects in humans. [ABSTRACT FROM AUTHOR]

Summary: This study assessed the ability of near‐infrared spectroscopy to predict intramuscular fat (IMF) and protein content of freeze‐dried ground beef and sheep meat determined using the modified Soxhlet extraction and Dumas combustion, and ascertain if robust calibration models could be developed for both assays using the combined spectral data from both species. Samples were sourced from sheep and cattle slaughtered for a variety of experiments, which covered a range in age, diet fed and carcase cut. All samples were scanned using a benchtop NIRS instrument to develop calibration models, a subset of which was used for later validation. Intramuscular fat and protein content of samples ranged from 5.1 to 32.8 and 63.4 to 89.8, respectively, with combined species of the R2 values of 98.4 and 96.5 (RMSE 0.74 and 0.76) for IMF and protein respectively. Additionally, animal age and carcase cut were found to have no significant impact on the precision of prediction models. Results from our study showed that individual species as well as combined calibration models can be successfully developed for predicting IMF and protein content of freeze‐dried ground beef and sheep meat. [ABSTRACT FROM AUTHOR]

Summary: The naked barley was germinated and then carried out with hot air‐ or infrared drying to explore the physicochemical and functional properties of protein isolated from barley. Moreover, the relationship between protein and the noodles made from wheat and germinated barley flour was evaluated. It was found that germination affected the protein properties, and the protein properties were correlated with the properties of noodles. The content of β‐sheet in protein was first increased and then decreased with germination time increased, and the protein had larger emulsification and foaming properties. Besides, the protein isolated from hot air‐dried germinated barley had higher gelatinisation enthalpy and secondary structure content. Furthermore, the wheat and germinated barley mixed noodles had increased elasticity and cohesiveness and reduced viscosity and water absorption. The hardness of noodles showed was positively correlated with water absorption capacity, and the extensibility of cooked noodles was positively correlated with the foaming capacity of proteins. [ABSTRACT FROM AUTHOR]

Summary: This study evaluated effects of enzymatic, extrusion and combined pretreatments on functional and thermal properties of protein concentrates from defatted rice bran to improve their applicability to food formulations. After the pretreatments, protein concentrates were recovered by alkaline solubilisation and isoelectric point precipitation. Water absorption capacity, oil absorption capacity, emulsifying and foaming properties, and thermal stability were determined in protein concentrates. Yields of each pretreatment were above 62% protein. Enzymatic hydrolysis increased all functional properties studied, mainly for emulsifying activity index (an increase of 71.1%) and foaming capacity (an increase of 60.3%). The extrusion affected positively the oil absorption capacity, emulsifying activity index and foaming capacity. The combined process was able to raise the functional properties. The principal component analysis confirmed that 95.5% improvement in functional properties of concentrates had a strong positive correlation with the pretreatments. However, the pretreatments affected thermal stability and the enthalpy of denaturation negatively. [ABSTRACT FROM AUTHOR]

Summary: The effects of flour treatment methods, including with glucose oxidase (GOX), lipoxygenase (LOX), xylanase and heating for 1 h at 37 °C (HEAT), on protein aggregation during the flour maturation were investigated. GOX has strong oxidising effects; LOX not only oxidises, but also may affect unsaturated fatty acids; xylanase degrades sugar molecules; HEAT can accelerate the thermal motion of molecules. Data analysis after treatment with GOX, LOX, xylanase and HEAT revealed that the glutenin macropolymer content increased by 0.43%, 0.87%, 0.39% and 0.62%, and the median size of the sample (D50) increased by 1.56, 1.64, 0.52 and 0.74 μm, respectively. In addition, the proportion of a random coil and β‐sheet increased and that of α‐helix and β‐turns decreased, while the polymeric protein content increased. This study contributes to our understanding of the protein changes during flour maturation and helps to predict the quality of wheat flour. [ABSTRACT FROM AUTHOR]

Consumer appeal for ready-to-eat (RTE) products is forecast to grow rapidly over the next 5 years as consumers demand convenient snacks with exciting sensory and textural properties. Extrusion technology has been used extensively in the production of cereal RTE snacks due to its ease of operation and ability to produce a variety of textures and shapes which appeal to consumers. Many of the existing RTE products are relatively high in sugar and salt, thus being regarded as energy dense but nutritionally poor foods. However, there exists a potential to manipulate the nutritional status of extruded RTEs by altering the digestion potentials of starch and protein, and by the incorporation of bioactive components such as dietary fibre. The review article explores some of the recent research in this field and illustrates opportunities by which the global food industry could react to consumers' requirements for healthful RTE snack products in the coming years. [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]

Protein content and content of some antinutrients were determined in four Vigna unguiculata (L) Walp and three Vicia faba cultivars frequently consumed in Brazil. The V. faba cultivars showed higher protein contents [26.8%–27.2% (w/w)] than the V. unguiculata cultivars [20.5%–22.5% (w/w)]. The difference was, however, not statistically significant ( P ≥ 0.05). Compared with the V. unguiculata cultivars, the V. faba cultivars exhibited a significantly higher content of all antinutritional factors analysed. In V. faba, condensed tannins ranged from 1.95 to 2.87 g eq. catechin (CE) kg−1, polyphenols from 4.81 to 7.21 g kg−1, phytate from 12.7 to 14.3 mmol kg−1, trypsin inhibitor activity from 4.12–4.38 TIU mg−1 and haemagglutinating activity from 51.3 to 57.2 HU kg−1; whereas in V. unguiculata, the corresponding values were determined to be 0.97–1.81 g eq. CE kg−1 for condensed tannins, 5.87–6.62 g kg−1 for polyphenols, 8.7–12.6 mmol kg−1 for phytate, 3.09–3.56 TIU mg−1 for trypsin inhibitor activity and 0.5–0.6 HU kg−1 for haemagglutinating activity. [ABSTRACT FROM AUTHOR]

This study assessed the film-forming abilities of six types of proteins, as well as six types of polysaccharides at various concentrations (proteins: 0–16%; polysaccharides: 0–4%) and heating temperatures (60–80 °C). Biopolymer films evaluated included: sodium caseinate (SC), whey protein isolate (WPI), gelatine (G); caboxymethyl cellulose (CMC), sodium alginate (SA) and potato starch (PS). Screening trials showed that optimal film-forming conditions were achieved using SC and G (4% and 8%), WPI (8% and 12%), PS, CMC (2% and 3%) or SA (1% and 1.5%) solutions heated to 80 °C in combination with 50% (w/w) glycerol. Films manufactured from 1.5% SA, 8% G and 3% CMC had the highest tensile strength (24.88 MPa); flexibility (89.69%)/tear strength (0.30 N) and puncture resistance (22.66 N), respectively. SC, WPI and G-based films were more resistant to solvent than SA, CMC and PS. Film permeability to water vapour and oxygen decreased in the order: 12% WPI to 1% SA and 12% WPI to 1% SA. All films tested were impermeable to oil. [ABSTRACT FROM AUTHOR]

Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (⩾200 °C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential. [ABSTRACT FROM AUTHOR]

The use of dry whole milk, skimmed milk, caseinate, regular and modified whey, at 2% level (w/w) and with 2% additional protein level was studied in a chicken breast meat system with 51% water addition. At the 2% (w/w) level, all dairy proteins significantly reduced cooking loss compared with the control, with caseinate showing the best results. When compared on an equal protein level (2% total protein), the best performing ingredients were the whole milk and modified whey. A similar observation was made in their effect on the products’ hardness and fracturability. A cost analysis revealed that modified whey provided the most economical ingredient even when used in quantities three times greater than that of as caseinate. Microscopy results showed the formation of larger fine-protein-matrix regions in the treatments that provided higher fracturability values. [ABSTRACT FROM AUTHOR]

Filtration and centrifugation for separating functional proteins from an alkaline solubilisation process are investigated. The influence of the method of separation on the yield and the gel quality of surimi produced from the protein isolates was studied. The possibility of replacing centrifugation by filtration is investigated for a first and a second centrifugation step where the first centrifugation separates a dissolved protein phase at high pH from undissolved material and the second centrifugation separates precipitated proteins from the waterphase at neutral pH. The separation method greatly affects the yield and the quality of the processed surimi. Replacing the first centrifugation with sieving improves the yield of protein isolate, but worsens the quality of the produced gel. Replacing the second centrifugation with filtration has no influence on the yield or the quality of the protein isolate. [ABSTRACT FROM AUTHOR]

Determination of wheat flour quality parameters, such as protein, moisture, dry mass by wet chemistry analyses takes long time. Near infrared spectroscopy (NIR) coupled with multivariate calibration offers a fast and nondestructive alternative to obtain reliable results. However, due to the complexity of the spectra obtained from NIR, some wavelength selection is generally required to improve the predictive ability of multivariate calibration methods. In this study, two different wheat data sets are investigated with the aim of establishing successful calibration models using NIR spectra of wheat samples. The first data set (material 1) was obtained from the ftp address ( ) and contained 100 NIR spectra of wheat of which wet chemical analysis of protein and moisture content were done with reference methods. The second data set (material 2) contained 176 spectra and was downloaded from . This wheat data set was given with the quality parameters, such as protein content, moisture content, other residues, dry mass, protein content in dry mass and hardness that were determined previously. Multivariate calibration models generated with genetic inverse least squares method demonstrated very good prediction results for the parameter mentioned here. Overall, the average per cent recoveries (APR) ranged between 99.23% and 100.34% with a standard deviation (SD) ranging from 0.34 to 3.15 for all the parameters investigated, except hardness. The APR value of hardness was 103.32 with the SD of 14.97. [ABSTRACT FROM AUTHOR]

The effect of sugars (sucrose, glucose and xylose) at different concentrations (0, 10, 20, 30, 40 and 50%) on the dynamic rheological properties of gelatine (2% w/w) was investigated during ageing. Storage moduli (G′), when measured at 5 °C, decreased with increasing concentration of added sugar. Xylose was found to induce the greatest reduction in the values ofG′.G′ values, measured as a function of ageing time (10 h) at 5 °C, increased rapidly at the initial stage and then reached a pseudoplateau region after long ageing times. Increasing the sugar concentration resulted in a decrease in the pseudoplateau values. The rate constant (K) for structure development of gelatine during ageing was described by apparent first-order kinetics.G′ andKvalues in gelatine–sugar composites increased in the following order: xylose < glucose < sucrose. The magnitudes ofG′ at the end of ageing were much greater than those ofG′′, showing a small dependence (slope = 0.005–0.088) on frequency (ω). [ABSTRACT FROM AUTHOR]

Phaseolus angularis (red bean) seeds contain about 25% protein (dry basis), almost half of which is globulin. Similar to globulins from other Phaseolus species , 7S vicilin is the major fraction of red bean globulin (RBG), with 11S legumin as a minor component. The amino acid profile of RBG met or exceeded the FAO/WHO standard. Circular dichroism measurements indicate that RBG is a protein rich in α-helical and β-turn structures. RBG exhibited higher protein solubility than Supro 610, a commercial soy protein isolate, especially at acidic pHs, with minimal solubility at around pH 5.0. Compared to Supro 610, RBG had lower water hydration capacity and comparable fat binding capacity, which might be because of its lower surface hydrophobicity. RBG had higher emulsifying activity index and emulsion stability than Supro 610, but with poorer foaming properties. [ABSTRACT FROM AUTHOR]