Effects of ball milling treatment on physicochemical properties and digestibility of Pacific oyster (Crassostrea gigas) protein powder

Phycobiliprotein from Arthrospira maxima: Conversion to nanoparticles by high-energy ball milling, structural characterization, and evaluation of their anti-inflammatory effect

Arthrospira maxima is a source of phycobiliproteins with different nutraceutical properties, e.g. antioxidant and anti-inflammatory activities. The current study was aimed at the elaboration, characterization, and evaluation of the anti-inflammatory effect of the phycobiliprotein nanoparticles extracted from Arthrospira maxima. Previously freeze-dried phycobiliproteins were milled by high-energy ball milling until reaching a nanometric size (optimal time: 4 h). Microscopy techniques were used for the characterization of the size and morphology of phycobiliproteins nanoparticles. Additionally, a spectroscopic study evidenced that nanosized reduction induced an increase in the chemical functional groups associated with its anti-inflammatory activity that was tested in a murine model, showing an immediate inflammatory effect. The novelty and importance of this contribution was to demonstrate that high energy ball milling is an emerging and green technology that can produce phycobiliprotein nanoparticles on a large-scale, without the use of organic solvents, to test their nutraceutical properties in a biological model by intragastric administration.

Characterisation of the protein quality and composition of water kefir-fermented casein

This study aimed to assess the technique of natural fermentation by applying water kefir to the casein protein. The diverse microorganisms and their enzymes found naturally in the water kefir can influence casein's characteristics. The fermented casein's protein quality (digestibility and secondary protein structure) and composition (total soluble solids and nutritive and non-nutritive substances) were investigated. Our findings revealed that the fermented casein's protein digestibility and total phenolic content increased from 82.46 to 88.60 % and 7.6 to 8.0 mg gallic acid equivalent/100 g, respectively. In addition, their surface charge and hydrophobicity changed from -30.06 to -34.93 mV and 286.9 to 213.7, respectively. Furthermore, the fermented casein's secondary protein components, α-helix (decreased from 13.66 to 8.21 %) and random coil (increased from 16.88 to 19.61 %), were also altered during the fermentation. Based on these findings, the water kefir fermentation approach could be an effective, practical, non-thermal approach for improving casein's protein quality and composition.

The changed structures of Cyperus esculentus protein decide its modified physicochemical characters: Effects of ball-milling, high pressure homogenization and cold plasma treatments on structural and functional properties of the protein

Three physical treatments, including ball-milling (BM), high pressure homogenization (HPH) and cold plasma (CP) were applied to modify structural and functional properties of Cyperus esculentus protein (CEP). The results showed that three treatments significantly altered morphology and reduced particle size of CEP. Both primary and secondary structures of CEP were hardly changed, while disulfide bonds and hydrophobic forces between amino acid residues of CEP were interrupted by three treatments, releasing free sulfhydryls and hydrophobic groups. With the free moiety accumulation, the reformed interactions between them enhanced the crystallinity and thermostability of CEP. Besides, solubility and emulsifying properties of CEP were significantly improved within a certain range of treatment duration and intensity, and three treatments decreased water but increased oil holding capacity of CEP. Conclusively, the modified physicochemical properties of CEP were decided by the changed molecular structures of CEP, and different treatments may satisfy different processing requirements for the protein.

Newly developed care food enhances grip strength in older adults with dysphagia: a preliminary study

BACKGROUND/OBJECTIVES

Maintaining total muscle mass in the older adults with swallowing difficulty (dysphagia) is important for preserving swallowing function. Increasing protein intake can help sustain lean body mass in the older adults. The aim of this study was to evaluate the effect of various high-protein texture-modified foods (HPTMFs) on muscle mass and perform dietary assessment in ≥ 65-yrs-old patients with dysphagia.

SUBJECTS/METHODS

Participants (n = 10) received the newly developed HPTMFs (average 595.23 ± 66.75 kcal/day of energy, 54.22 ± 6.32 g/day of protein) for 10 days. Relative hand-grip strength (RHS), mid-upper arm circumference (MUAC), body composition, mini nutritional assessment (MNA), mini dietary assessment (MDA), and Euro Quality-of-Life questionnaire 5-dimensional classification (EQ-5D) were assessed.

RESULTS

After 10 days, an increase in MUAC (26.36 ± 2.35 cm to 28.50 ± 3.17 cm, P = 0.013) and RHS (0.38 ± 0.24 kg/kg body weight to 0.42 ± 0.22 kg/kg body weight, P = 0.046) was observed. Although MNA, MDA, EQ-5D, subjective health status, muscle mass, and calf circumference showed a tendency to increase after intervention, no significant differences were found.

CONCLUSIONS

These results suggest that the HPTMFs can be used for improving the nutritional and health status in patients with dysphagia.

Functionality Enhancement of Pea Protein Powder via High-Intensity Ultrasound: Screening in-vitro Digestion, o/w Emulsion Properties and Testing in Gluten-Free Bread

Structural modification of protein prior to food application is an emergent approach to improve functionalization. The effectiveness of high-power ultrasound at varying amplitudes (0-100%) on the properties of pea protein powder was investigated in this study. The resulting modification was also tested with model gluten-free bread formulation and by screening the emulsion properties within vegetable oil. The 50% and beyond amplitude levels had significant impact on protein solubility, viscosity, Fourier Transform Infrared (FTIR) spectra, emulsion activity and stability. Foaming capacity and stability were enhanced with 75 and 100% amplitudes while the 25% amplitude exhibited the highest absolute zeta-potential. There was a concomitant increase in ultrasound amplitude and oil-binding capacity (2.83-6.43 g/g) where the water-holding capacity gradually decreased (5.78-3.61 g/g) with the increase in ultrasound power. The increase in ultrasound power led to decrease in L* values but progressively increased the total color difference (ΔE). Sonication (50% amplitude) also promoted the in-vitro digestibility of proteins by 22% as compared to the untreated sample. Scanning electron microscopy (SEM) fairly depictured the structural modification and FTIR spectra clearly demonstrated conformational changes in protein powders. The fortification with restructured pea protein powder significantly affected the volume and adhesiveness of glutenfree bread.

Structure characteristics and physicochemical property of starch, dietary fiber, protein in purple corn flour modified by low temperature impact mill

The structural changes of macromolecules (starch, dietary fiber and protein) in purple corn flour (PCF) modified by a low temperature impact mill (LTIM) at different air classifier speed (ACS) were investigated. LTIM changed the multi-scale structure of starch, which was characterized by increased starch damage, stronger destruction of relative crystallinity (from 37.85 % to 15.53 %) and short-range ordered structure (R_1047/1022, from 1.21 to 0.73) with the increased ACS. The structure of dietary fiber was also destroyed on multi-level, including decreased particle size, destructive morphology, and slightly changed crystalline structure. Additionally, LTIM showed high damage on the senior structure (surface hydrophobicity, disulfide bond, secondary structure) of protein. Due to the structure changes modified by LTIM, starch, dietary fiber and protein played different role on hydration property of PCF. Starch had positive effect, while dietary fiber and protein had negative effect. Our experimental results may provide valuable information for further analysis of other quality changes (oil holding capacity, cation exchange capacity, ability to produce high-quality dough or end-out products, etc.) of purple corn flour after LTIM treatment.

Pea protein isolate characteristics modulate functional properties of pea protein-cranberry polyphenol particles

Plant polyphenols have a natural binding affinity for proteins, and their interaction can be exploited to form diverse aggregate particles. Protein-polyphenol particles utilized as food ingredients allow consumers to incorporate more health-benefiting plant bioactives into their diets. The functional properties of the protein-polyphenol particles can be influenced by many factors, including complexation conditions and starting material properties. Here, cranberry polyphenols extracted from pomace were complexed with nine pea protein isolate starting materials with different physical (particle size and protein content) and chemical (hydrolyzed and oxidized) properties to investigate the impact of protein characteristics on particle functionality. Chemical differences between proteins affected polyphenol binding; oxidized protein isolate (specifically, VegOtein N) bound 12%-27% more polyphenols than other isolates. Polyphenol binding to proteins decreased digestion rates in vitro, averaging 25% slower gastric (pepsin) digestion and a 35% slower intestinal (pancreatin) digestion. Physical differences in protein starting materials affected digestibility; isolate with the largest particle size (specifically, Nutralys F85G) produced particles with the lowest digestion rate. Solubility was impacted by both the process of forming particles and by polyphenol binding; control particles were 56% less soluble, and protein-polyphenol particles up to 75% less soluble, than unmodified proteins. The solubility of unmodified protein isolate starting materials varied widely according to the manufacturing process, but, after complexation, protein-polyphenol particles produced from all protein sources exhibited a similar depressed level of solubility. The desired functional properties of the protein-polyphenol particle food ingredients will be considerably influenced by the properties of the protein isolate starting material.

Effects of superfine grinding using ball-milling on the physical properties, chemical composition, and antioxidant properties of Quercus salicina (Blume) leaf powders

BACKGROUND

Quercus salicina (Blume) leaves are traditionally used as folk medicine in some Asian countries. The aim of this study was to evaluate the effects of ball milling for different periods (0, 6, 12, 18, and 24 h) on the physicochemical properties of superfine Quercus salicina (Blume) leaf (QSL) powders.

RESULTS

The particle sizes, water-holding capacity, angle of repose, and redness of the superfine QSL powder decreased with increasing ball-milling times, whereas the water solubility index, bulk density, tapped density, brightness, and yellowness were found to increase. Significantly higher (P > 0.05) total phenolic and flavonoid contents, and antioxidant activities, were observed for the superfine QSL powders obtained after 24 h ball-milling time. A total of 12 phenolic compounds in free and cell-wall-bound forms were quantified in the superfine QSL powder. Free phenolics such as protocatechuic acid, caffeic acid, rutin, and p-coumaric acid were increased and all cell-wall-bound phenolics were decreased with increasing ball-milling times. The antioxidant activity of the free phenolics increased with increasing ball-milling times, and the cell-wall-bound forms decreased.

CONCLUSION

Superfine grinding by ball milling for 24 h can thus be used to produce superfine QSL powder with higher free phenolic metabolite content and antioxidant activity, and improved water solubility index, color, bulk, and tapped densities. This study will be useful for the food / nutraceutical / pharmaceutical industries in the manufacturing of active food ingredients or value-added products using QSL powders. © 2020 Society of Chemical Industry.

Modification of the structural and functional properties of wheat gluten protein using a planetary ball mill

The modification of the structure and function of wheat gluten because of planetary ball milling was investigated. Reduced SDS-PAGE revealed that the subunit compositions and bands of gluten did not change with an increase in grinding time. FTIR analysis showed that α-helices and β-sheets decreased, whereas β-turns increased, indicating that the secondary structure of gluten became looser and more disorderly. Owing to the mechanical force of planetary ball milling constantly breaking the disulfide bonds in gluten, the number of free sulfhydryl groups increased, and surface hydrophobicity increased from 940.97 to 1197.50 after 20 min ball-milling treatments, whereas the foaming capacity was improved from 8.7 to 31 cm³. After 40 min, mastersizer analysis showed that particle size decreased from 85.9 to 32.3 μm, and the whiteness increased from 49.51 to 65.59. These results indicate that planetary grinding technology improves the functional properties of wheat gluten and expands its application potential.

Non-thermal processing has an impact on the digestibility of the muscle proteins

Muscle proteins undergo several processes before being ready in a final consumable form. All these processes affect the digestibility of muscle proteins and subsequent release of amino acids and peptides during digestion in the human gut. The present review examines the effects of different processing techniques, such as curing, drying, ripening, comminution, aging, and marination on the digestibility of muscle proteins. The review also examines how the source of muscle proteins alters the gastrointestinal protein digestion. Processing techniques affect the structural and functional properties of muscle proteins and can affect their digestibility negatively or positively depending on the processing conditions. Some of these techniques, such as aging and mincing, can induce favorable changes in muscle proteins, such as partial unfolding or exposure of cleavage sites, and increase susceptibility to hydrolysis by digestive enzymes whereas others, such as drying and marination, can induce unfavorable changes, such as severe cross-linking, protein aggregation, oxidation induced changes or increased disulfide (S-S) bond content, thereby decreasing proteolysis. The underlying mechanisms have been discussed in detail and the conclusions drawn in the light of existing knowledge provide information with potential industrial importance.

Influence of Age and Individual Differences on Mouthfeel Perception of Whey Protein-Fortified Products: A Review

Protein needs are considered to increase with age, with protein consumption being associated with many positive outcomes. Protein-fortified products are often used to improve nutritional status and prevent age-related muscle mass loss in older adults. Accordingly, older adults are commonly provided with products fortified with whey protein; however, such products can cause mouthdrying, limiting consumption and product enjoyment. Currently, the extent to which age and individual differences (e.g., saliva, oral health, food oral processing) influence the perception of whey protein-derived mouthdrying is relatively unclear. Previous research in this area has mainly focused on investigating mouthdrying, without taking into account individual differences that could influence this perception within the target population. Therefore, the main focus of this review is to provide an overview of the relevant individual differences likely to influence mouthfeel perception (specifically mouthdrying) from whey protein-fortified products, thereby enabling the future design of such products to incorporate better the needs of older adults and improve their nutritional status. This review concludes that age and individual differences are likely to influence mouthdrying sensations from whey protein-fortified products. Future research should focus more on the target population and individual differences to maximise the benefits from whey protein fortification.

Effects of flavourzyme addition on physicochemical properties, volatile compound components and microbial community succession of Suanzhayu

Flavourzyme is known to promote protein decomposition, resulting in more peptides and amino acids which can improve the quality of fermented foods. In this study, the effects of flavourzyme addition on the fermentation of Suanzhayu fish were investigated. The results showed that the addition of 50 U/g flavourzyme reduced the water activity (a_w) of products and promoted the release of trichloroacetic acid (TCA)-soluble peptides and free amino acids (FAAs). Thus, the stability of the product was improved and its nutritional value was increased. In addition, with the addition of flavourzyme, Lactobacillus and Saccharomyces more quickly became the dominant genera in the fermentation. Furthermore, the formation of alcohols, aldehydes, and esters was promoted in flavourzyme addition group. Redundant analysis (RDA) indicated that Lactobacillus and Lactococcus play important roles in the formation of flavors, especially for the characteristic flavors of Suanzhayu. Flavourzyme addition may be a novel method to greatly improve the properties of Suanzhayu and shorten the fermentation time.

Biological and conventional food processing modifications on food proteins: Structure, functionality, and bioactivity

Food proteins are important nutrients for human health and thus make significant contributions to the unique functions of different foods. The modification of proteins through physical and biological processing could improve the functional and nutritional properties of food products; these changes can be attributed to modifications in particle size, solubility, emulsion stability, secondary structure, as well as the bioactivities of the proteins. Physical processing treatments might promote physical phenomena, such as combined friction, collision, shear forces, turbulence, and cavitation of particles, and lead to changes in the particle sizes of proteins. The objective of this review is to illustrate the effect of physical and biological processing on the structure, and physical and chemical properties of food-derived proteins and provide insights into the mechanism underlying structural changes. Many studies have suggested that physical and biological processes, such as ultrasound treatment, high pressure homogenization, ball mill treatment, and enzymatic hydrolysis could affect the structure, physical properties, and chemical properties of food-derived proteins. Some important applications of food-derived proteins are also discussed based on the relationships between their physical, chemical, and functional properties. Perspectives from fundamental or practical research are also brought in to provide a complete picture of the currently available relevant data.

Mechanochemically Induced Controlled Glycation of Lysozyme and Its Effect on Enzymatic Activity and Conformational Changes

Protein glycation through heating of a mixture of protein and reducing sugars is one of the most commonly used methods of protein modification; however, in most cases, this approach can lead to uncontrolled glycation. The hypothesis that mechanical energy supplied through ball milling can induce glycation of proteins was tested using a well-characterized enzyme lysozyme. The Q-TOF/MS analysis of the milled samples has indicated that the milling of sugar-protein mixtures in stainless steel jars for 30 min and at a frequency of 30 Hz generated mainly monoglycated proteins even with the highly reactive ribose. Increasing the sugar concentration or the milling time did not influence the overall yield or generate more glycoforms. Enzymatic activity measurements, FTIR, and fluorescence spectroscopic studies have indicated that milling of lysozyme alone leads to a significant loss in enzymatic activity and structural integrity in contrast to milling in the presence of sugars.