STUDYINGTHE EFFECTOF FLOURAND LUPINE PROTEIN CONCENTRATE MCORPORATIONON PHYSICAL CHEMICALAND SENSORY PROPERTIESOF BISCUIT

The purpose of this study was to determine the effect of lupine flour (L.f) and lupine protein concentrate (L.P.C) incorporation on chemical, nutritional and sensual qualities characteristics of biscuit (L.P.C) was prepared by isoelectric precipitation method. A standard recipe for biscuit preparation by wheat patent flour used as the control. Wheat flour in the control treatment was replaced with (L.f) and (L.P.C) at levels 10, 20 & 30%. Chemical composition of (L.f), (L.P.C) and biscuit treatments were studied. Results showed that protein contents were 35.35 & 75.80% for (L.F) and (L.P.C), respectively. While they amounted to 14.70, 16.16 & 18.61% for (L.f) incorporated biscuits and 15.20, 18.09 & 21.08% for (L.P.C) incorporated biscuits at the substitution levels studied, respectively compared 12.43% control. Results also indicated contents of total dietary fibers and tannins in (L.f),( L.P.C) and biscuits prepared. Sensory evaluation of biscuit treatments revealed that there was significant decrease at substitution level up to 30% of (L.f) except color score, while all scores of sensory properties were improved significantly at all substitution levels of (L.P.C). Spread ratio was affected adversely by incorporation of (L.f) and slightly when (L.P.C) used. Results showed a reduction in biscuit tenderness during storage. Reverse to the above statement with 30% incorporation of (L.f) while increased at (L.P.C) treatments. The study demonstrated that (L.f) and (L.P.C) can be incorporated into biscuits formulation by replacing up to 20, & 30% of wheat flour control 12.43%, respectively to increase dietary fiber and protein contents.

Improvements in the production of purified M13 bacteriophage bio-nanoparticle

M13 bacteriophage is a well-established versatile nano-building block, which can be employed to produce novel self-assembled functional materials and devices. Sufficient production and scalability of the M13, often require a large quantity of the virus and thus, improved propagation methods characterised by high capacity and degree of purity are essential. Currently, the ‘gold-standard’ is represented by infecting Escherichia coli cultures, followed by precipitation with polyethylene glycol (PEG). However, this is considerably flawed by the accumulation of contaminant PEG inside the freshly produced stocks, potentially hampering the reactivity of the individual M13 filaments. Our study demonstrates the effectiveness of implementing an isoelectric precipitation procedure to reduce the residual PEG along with FT-IR spectroscopy as a rapid, convenient and effective analytic validation method to detect the presence of this contaminant in freshly prepared M13 stocks.

Utilisation of isoelectric precipitation to recover fish protein isolate from seafood processing waste

Threadfin bream (Nemipterus japonicus) is an important marine fish species used in the preparation of surimi. The waste generated from surimi production contains large quantity of recoverable proteins, which could be utilised for byproduct development. In this study, Isoelectric precipitation (IEP) technique as a method to recover proteins from fish processing waste was attempted. The alkali aided IEP process extracted the fish protein isolate (FPI) efficiently with a yield of 84.13±0.11%. The highest protein yield was recorded at a homogenised sample to water ratio of 1:9. Maximum protein content was found at pH 13 with 19.63 ±0.52% yield. FPI extracted had higher protein content, less ash and low lipid contents compared to the fish processing waste. The mean yield and protein composition of FPI extracted atdifferent treatments of pH and sample to water ratiowere found to be significantly different (p<0.05). Sample to water ratio of 1:9 and pH 13 was found to be the best combination among the different treatments attempted for FPI extraction from threadfin bream processing waste.

Development of optimal method of obtaining pea isolated proteins for use in breeding for quality

The article provides the results of the experiments on determination of optimal parameters for obtaining isolated proteins from grains of cultivated and wild pea for use in breeding for quality. The flour of pea varieties Sophia, Rodnik and wild accession k-3370 (Pisum sativum L. ssp. Elatius) were used in the experiment. Isolated pea proteins were obtained based on alkaline extraction and isoelectric precipitation. The experiments were carried out with the use of complete and fractional factorial plans with two levels of factors. Extraction and precipitation of protein were conducted in two stages. One hundred grams of flour were used for extraction. Influence of factors (variety, pH, duration of extraction) on the yield of isolated protein, extraction efficiency, crude protein and fat content in protein isolates was studied. All isolates were characterized by high content of crude protein (90.2-93.1 %). It was determined that increase of pH higher than eight led to enhancement of protein yield and decrease of crude protein content. The results obtained raise the possibility of effective extraction at decreased level of pH that prevents the formation of toxic chemicals. Increase of pH promoted fat accumulation in protein isolate especially at the second stage of extraction. Thus, obtaining protein isolates for evaluation of pea genetic resources should be conducted during a single cycle of extraction and precipitation. The experiments have not revealed significant differences between cultivated and wild pea as to the technology of extraction. The results of the studies are important for evaluation of pea genetic resources according to functional properties of protein isolates.

Enhanced Solubility of Rapeseed Meal Protein Isolates Prepared by Sequential Isoelectric Precipitation

The solubility of plant protein isolates is a key determinant of their potential application. Two protein isolates (PI) from ethanol-treated industrial rapeseed meal, PI10.5–2.5 and PI2.5–8.5, were prepared by sequential isoelectric precipitation of alkali-extracted proteins (pH 12) starting from pH 10.5 to 2.5 or from pH 2.5 to 8.5, respectively. Biochemical analyses revealed that PI2.5–8.5 contained a higher amount of crude protein (72.84%) than PI10.5–2.5 (68.67%). In the same protein isolate, the level of total phenols (0.71%) was almost two-fold higher than that in PI10.5–2.5 (0.42%). No glucosinolates were established in both protein isolates. SDS-PAGE analysis demonstrated that PI10.5–2.5 contained 10 to 15 kDa protein fractions in a relatively higher amount, while PI2.5–8.5 was enriched in 18 to 29 kDa protein fractions. PI10.5–2.5 exhibited high solubility, varying from 41.74% at pH 4.5 to 65.13% at pH 6.5, while PI2.5–8.5 was almost two-fold less soluble under the same conditions. Up to pH 5.5, the addition of NaCl at 0.03 and 0.25 M diminished the solubility of PI2.5–8.5, while the solubility of PI10.5–2.5 was increased. The supplementation of PI10.5–2.5 with 0.25 M NaCl enhanced the protein solubility to 56.11% at pH 4.5 and 94.26% at pH 6.5. The addition of 0.03 M NaCl also increased the solubility of this protein isolate but to a lower extent. Overall, the approach for sequential precipitation of proteins influenced the biochemical characteristics, protein fractional profile and solubility of prepared protein isolates.

Comparison of Faba Bean Protein Ingredients Produced Using Dry Fractionation and Isoelectric Precipitation: Techno-Functional, Nutritional and Environmental Performance

Dry fractionated faba bean protein-rich flour (FPR) produced by milling/air classification, and faba bean protein isolate (FPI) produced by acid extraction/isoelectric precipitation were compared in terms of composition, techno-functional properties, nutritional properties and environmental impacts. FPR had a lower protein content (64.1%, dry matter (DM)) compared to FPI (90.1%, DM), due to the inherent limitations of air classification. Of the two ingredients, FPR demonstrated superior functionality, including higher protein solubility (85%), compared to FPI (32%) at pH 7. Foaming capacity was higher for FPR, although foam stability was similar for both ingredients. FPR had greater gelling ability compared to FPI. The higher carbohydrate content of FPR may have contributed to this difference. An amino acid (AA) analysis revealed that both ingredients were low in sulfur-containing AAs, with FPR having a slightly higher level than FPI. The potential nutritional benefits of the aqueous process compared to the dry process used in this study were apparent in the higher in vitro protein digestibility (IVPD) and lower trypsin inhibitor activity (TIA) in FPI compared to FPR. Additionally, vicine/convicine were detected in FPR, but not in FPI. Furthermore, much lower levels of fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs) were found in FPI compared to FPR. The life cycle assessment (LCA) revealed a lower environmental impact for FPR, partly due to the extra water and energy required for aqueous processing. However, in a comparison with cow’s milk protein, both FPR and FPI were shown to have considerably lower environmental impacts.

Production of White, Red and Black Quinoa (Chenopodium quinoa Willd Var. Real) Protein Isolates and Its Hydrolysates in Germinated and Non-Germinated Quinoa Samples and Antioxidant Activity Evaluation

Red, black and white seeds quinoa were germinated at 28 °C during 24 (G1), 48 and 72 h (G3). Red quinoa presented a higher percentage of germination with a value of 46% of germination at 72 h. Quinoa protein isolate (QPI) was obtained by alkaline extraction (pH 8.0) followed by an isoelectric precipitation (pH 4.5) from white, red and black quinoa seeds, germinated QPI-G1 or QPI-G3 and non-germinated QPI-NG, Chenopodium quinoa Willd var. Real. QPI-G1, QPI-G3 and QPI-NG were subject to a simulated gastric digestion (DG) and in vitro duodenal digestion (DD). The antioxidant activity was evaluated using the 1, 1-diphenyl-2-picryl hydrazyl (DPPH), azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) methods. Gastric and duodenal digest of QPI-NG and QPI-G1 and QPI-G3 from white, red and black quinoa presented antioxidant activity. QPI-G1-DD of white quinoa presented the highest antioxidant activity with a DPPH value of 167.98 µmoL TE/g of digest, QPI-G1-DD of red quinoa with an ABTS value of 204.86 µmoL TE/g of digest and QPI-G1-DD of black quinoa with an ORAC value of 401.42 µmoL TE/g of digest. QPI-G3-DD of white quinoa presented higher antioxidant activity with a DPPH value of 186.28 µmoL TE/g of sample, QPI-G3-DD of red quinoa with an ABTS value of 144.06 µmoL TE/g of digest and QPI-G3-DD of black quinoa with an ORAC value of 395.14 µmoL TE/g of digest. The inhibition of reactive oxygen species (ROS) production in the zebrafish embryo model (Danio rerio) was evaluated. Protein profiles of QPI from white, red and black from germinated quinoa and non-germinated quinoa were similar with proteins between 10 kDa to 100 kDa with the presence of globulins 11S and 7S and 2S albumins.