Effect of vegetable oil hydrogel emulsion as a fat substitute on the physicochemical properties, fatty acid profile, and color stability of modified atmospheric packaged buffalo burgers.

Buffalo burgers were prepared with 50% or 100% buffalo backfat substitution using walnut, and peanut oil emulsion gels (EGs) blended with chia flour. Burgers were stored at 2 °C in modified atmosphere packaging for 12 days. The fat replacement decreased total fat by 26% and increased ash by 34%. Hardness and chewiness decreased with increasing the fat replacement; however, it did not affect springiness and cohesiveness values. Burger reformulations led to an increase in cooking yield (10%). Walnut oil EGs increased PUFA level up to 458%. Both oils enhanced PUFA/SFA and ω-6/ω-3 ratios and atherogenic and thrombogenic indices. Concerning color attribute, about 66% reduction was observed in redness values during the storage period of 12 days. Moreover, the sensory scores for all attributes, i.e., appearance, odor, flavor, and juiciness, were in the acceptable range of five or above in the reformulated burgers. In conclusion, 50% fat substitution using walnut and peanut oil EGs improved the nutritional profile of buffalo burgers without compromising the technological and sensory characteristics.

Improvement on gel properties of myofibrillar protein from chicken patty with potato dietary fiber: Based on the change in myofibrillar protein structure and water state.

Influence of potato dietary fiber (PDF) on myofibrillar protein (MP) structure, aggregation behavior, and gel properties of chicken patty was evaluated. The Raman spectroscopy results indicated that the α-helix content decreased by 21.9 %, while ß-sheets content increased by 45.0 % in 3.0 % PDF sample compared with the control (P < 0.05), and aliphatic residues cross-linked. Particle size, turbidity, and the roughness of MP surface morphology increased, whereas the zeta-potential of MPs decreased with PDF increasing. The gelation process of MP with PDF proceeded at a fast rate and their elasticity and viscosity were high as determined by dynamic rheology. Gels with 3.0 % PDF exhibited significantly enhanced gel strength and a high WHC, which increased by 44.20 % and 22.5 %, respectively, compared with the control, PDF inhibited the transformation of immobilized water to free water and eliminated the water channels during heating as well as formed a more uniform and denser microstructure. Therefore, PDF can be a potential ingredient for improving the quality of processed meat products.

Future trends of processed meat products concerning perceived healthiness: A review.

The 21st-century consumer is highly demanding when it comes to the health benefits of food and food products. In the pursuit of attracting these consumers and easing the rise in demand for high-quality meat products, the processed meat sector is intensely focused on developing reformulated, low-fat, healthy meat products. Meat and meat products are considered the primary sources of saturated fatty acids in the human diet. Therefore, these reformulation strategies aim to improve the fatty acid profile and reduce total fat and cholesterol, which can be achieved by replacing animal fat with plant-based oils; it could be performed as direct inclusion of these oils or pre-emulsified oils. However, emulsions offer a viable option for incorporating vegetable oils while avoiding the multiple issues of direct inclusion of these oils in meat products. Processed meat products are popular worldwide and showing a gradually increasing trend of consumption. Various types of plant-based oils have been studied as fat replacers in meat products. This review will focus on possible methods to reduce the saturated fatty acid content in meat products.

Transglutaminase crosslinking promotes physical and oxidative stability of filled hydrogel particles based on biopolymer phase separation.

In the present study, the effect of transglutaminase (TGase) concentration on the physical and oxidative stabilities of filled hydrogel particles created by biopolymer phase separation was investigated. The results showed that filled hydrogels had relatively smaller particle sizes, higher absolute zeta-potentials, higher interfacial layer thicknesses and lightness values with the increasing of TGase concentration (P < 0.05), as evidenced by the apparent viscosity and viscoelasticity behavior. However, the relatively higher TGase concentration promoted the protein aggregation, which weakens the protection of the surface protein layer, having the negatively impacted the physical stability of filled hydrogels. Microstructural images which obtained via cryo-scanning electron microscopy also verified the above results. In particular, it is noted that filled hydrogels displayed the lowest degrees of lipid and protein oxidation during 10 days of storage (P < 0.05) at TGase concentration of 10 U/g. Prevention against oxidation was attributed mainly to TGase crosslinking of protein molecules on the surface of droplets, which likely provided a denser interface around lipid droplets. Our results indicated that TGase was a favourable agent to crosslink protein on the surface of lipid and improve the physical and oxidative stability of filled hydrogel particles.

Ultrasonic-assisted extraction of polyphenol from the seeds of Allium senescens L. and its antioxidative role in Harbin dry sausage.

The ultrasonic-assisted extraction of total polyphenol from Allium senescens L. (ASL) seeds was conducted, and the antioxidant efficacy of ASL seed extract (ASLSE) was assessed in Harbin dry sausages. ASLSE extracted with 1:30 g/mL water at 150 W for 15 min had the highest antioxidant capacities (P < 0.05). Subsequently, different addition levels (0, 2, 4, 6 and 8 g/kg) of freeze-dried ASLSE were applied in dry sausages during a twelve-day fermentation, and BHT treatment was the positive control. The lower pH values and carbonyl contents were detected in the treatments with 6 and 8 g/kg ASLSE than those in the other treatments at 12 d (P < 0.05). However, there was no difference in the water activity, lipid oxidation and color among the treatments with 6 and 8 g/kg ASLSE and 0.2 g/kg BHT (P > 0.05) at 12 d. These results indicated that 6 g/kg ASLSE could be effective in inhibiting lipid and protein oxidation and reducing color deterioration of dry sausages.

Physical properties and stability of filled hydrogel particles based on biopolymer phase separation: Influence of the ratio of protein to polysaccharide.

Filled hydrogel particles can be fabricated by incorporating an oil-in-water emulsion into portions of separated incompatible lower and upper phases together and remixing with later acidification to pH 5.0. The purpose of present study was to investigate the influence of different heat-denatured whey protein concentrates (HWPC)/high methoxy pectin (HMP) mass ratios (1:1, 2:1, 3:1, 4:1, and 5:1) of phase separated systems on the physical characteristics and stabilities of filled hydrogel particles. The results showed that the particle size of filled hydrogel particles significantly decreased with increasing HWPC/HMP mass ratios (P < 0.05), which was verified by reduced interfacial layer thickness. Moreover, decreased particle size also induced consistent reduction of the apparent viscosity and slightly increased the lightness. In particular, when the HWPC/HMP mass ratio was 3:1, the filled hydrogel particles exhibited the lowest amount of conjugated dienes and thiobarbituric acid-reactive substances after 10 days of storage (P < 0.05), which was mainly due to the highest amount of biopolymers distributed at the interfacial membrances (P < 0.05). Our results indicate that the phase separation system formed by HWPC/HMP mass ratio of 3:1 could be used to fabricate filled hydrogel particles with amplified stabilities at acidic pH for novel delivery systems.

Using a stable pre-emulsified canola oil system that includes porcine plasma protein hydrolysates and oxidized tannic acid to partially replace pork fat in frankfurters.

The objective of this study was to evaluate the effect of two different forms of canola oil (pure liquid form or a pre-emulsified form that includes porcine plasma protein hydrolysates modified by oxidized tannic acid) used for pork back-fat substitutions on the physico-chemical characteristics of frankfurters. When compared to the control group, partial replacement of pork back-fat using a pre-emulsified canola oil system exhibited excellent water and fat binding capacities, quicker relaxation times and lower amounts of saturated fatty acids (SFAs) (P < .05), as well as increased hardness, gumminess, and chewiness (P < .05) when verified by dynamic rheology analysis. Additionally, higher replacement ratio of pre-emulsified canola oil did significantly decrease the overall acceptability than the control group (P < .05). Our results indicate that pre-emulsified canola oil provided greater improvement with respect to the physical characteristics of partial pork back-fat replaced frankfurters, when compared to pure canola oil inclusion.

Textural and sensorial quality protection in frozen dumplings through the inhibition of lipid and protein oxidation with clove and rosemary extracts.

BACKGROUND: Oxidation is a major reason for nutritional and quality loss of dumplings during frozen storage. The addition of spice extracts in frozen dumplings may limit and inhibit oxidative impairments. In this study, the antioxidant effects of clove extract (CE) and rosemary extract (RE) and their influence on sensory and quality attributes of the meat-based filler in frozen pork dumplings stored at -18 °C were investigated. RESULTS: CE and RE significantly suppressed lipid and protein oxidation in terms of thiobarbituric acid-reactive substances and protein carbonyls (P < 0.05) formation. During frozen storage up to 180 days, the dumpling samples with antioxidants had a significantly higher breaking strength and lower cooking loss (P < 0.05) compared with the control, and the effect of RE was stronger than that of CE. Sodium dodecylsulfate polyacrylamide gel electrophoresis showed that samples with antioxidants had reduced protein crosslinking, hence less aggregation. Differential scanning calorimetry analysis proved that the dumplings with antioxidants during storage had a higher thermal stability than those of the control. Based on dynamic rheological testing, the addition of RE to dumpling fillers was more effective in enhancing the gelling capacity of myofibrillar protein compared to the control. Sensory panel results confirmed significant positive effects of both spice extracts on oxidative stability (reduced rancidity) and palatability (texture and juiciness) of dumplings. CONCLUSION: The addition of phenolic-rich CE and RE in dumpling processing is an excellent approach for the inhibition of sensory and quality deterioration associated with oxidation during frozen storage. © 2019 Society of Chemical Industry.

The enzymatic hydrolysis of soy protein isolate by Corolase PP under high hydrostatic pressure and its effect on bioactivity and characteristics of hydrolysates.

Enzymatic hydrolysis of soy protein isolate by Corolase PP under high hydrostatic pressure conditions was studied and the effects of hydrolysis on antioxidant and antihypertensive activities were investigated. As observed, high hydrostatic pressure (80-300MPa) enhanced the hydrolytic efficiency of Corolase PP and decreased the surface hydrophobicity of the hydrolysates. Hydrolysates obtained at 200MPa for 4h had higher bioactivities (reducing power, ABTS radical-scavenging and ACE inhibitory activities). The molecular weight (MW) determination indicated that hydrolysis at high hydrostatic pressure could increase the production of small peptides (<3kDa) and the amino acid sequences of these peptides with different inhibitory abilities, less than 3kDa, in hydrolysates were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI TOF MS). These results indicated that high hydrostatic pressure combined with Corolase PP treatments could be used as a potential technology to produce bioactive peptides from soy protein isolate.

Cooperative antioxidative effects of zein hydrolysates with sage (Salvia officinalis) extract in a liposome system.

This study investigated the cooperative antioxidative effects of sage extract (SE) and zein hydrolysates (ZH). The combination of 3mg/ml ZH and 10µg/ml SE exhibited a significant synergism in inhibition of the formation of thiobarbituric acid-reactive substances and provided superior protection of liposomes against oxidation. Zeta-potential results revealed that the interactions between liposomes and ZH were electrostatic interactions. Particle size determination further proved that ZH and SE added to oxidized liposomes significantly decreased the mean particle size. Confocal laser scanning microscopy revealed that when ZH was present in the liposome oxidizing system, the droplet sizes were obviously decreased compared to oxidized samples. ZH dispersed more uniformly and the interfacial membrane was more compact in the ZH-SE liposome. Transmission electron microscopy conveyed that the ZH-SE complex around the liposome particles could form a denser network structure, preventing radicals and oxidants from the approach of the liposomes.

The effectiveness of clove extracts in the inhibition of hydroxyl radical oxidation-induced structural and rheological changes in porcine myofibrillar protein.

Oxidation is a major cause of protein quality deterioration during the storage and processing of food. This study investigated the effects of clove extract (CE) on structural and rheological changes in porcine longissimus myofibrillar proteins (MP) and the effects of oxidizing radicals produced by a Fenton reaction system (FRS). Increased oxidation time was accompanied by increased carbonyl content, reduced Ca-ATPase activity, decreased enthalpy of denaturation, decreased thermal transition temperatures (P<0.05), and increased protein susceptibility to thermal aggregation. The addition of CE significantly inhibited carbonyl formation (P<0.05), enhanced solubility and thermal stability, and improved the gel formation ability (storage modulus, loss modulus) of MP. The protective effect of CE on protein denaturation was demonstrated by its efficacy in maintaining Ca-ATPase activity and decreasing the degree of protein aggregation. Overall, the hydroxyl radical-induced loss of the structural and functional properties of MP was significantly reduced by the presence of CE.

Potato starch oxidation induced by sodium hypochlorite and its effect on functional properties and digestibility.

The effects of different concentrations of sodium hypochlorite (active chlorine content at 0.1, 0.2, 1.0, 2.0, 3.0, and 4.0 g/100 g) on the properties of potato starch (PS) were investigated by determining the morphological, physicochemical, crystallinity, pasting, gel texture and digestive properties. The starch granules of PS oxidized with high oxidant concentrations caused cracks and pores, and oxidation mainly acts on the amorphous regions of the starch granules. As the sodium hypochlorite concentration increases, the carbonyl content, carboxyl content, solubility, and pasting temperature of PS increased, as measured using a Rapid Visco Analyser (RVA). The swelling power, breakdown, setback, and peak and final viscosities decreased according to the RVA (P<0.05). The gel strength increased under low-intensity oxidative treatments and decreased under high-intensity oxidative treatments. Oxidative treatment decreased the digestibility of gelatinized potato starch. The slowly digestible starch and resistant starch contents increased significantly, while the rapidly digestible starch content decreased after the oxidation modification (P<0.05). Overall, PS oxidation with sodium hypochlorite improved the functional characteristics of starch and decreased starch digestibility.

Antioxidant activity of black currant (Ribes nigrum L.) extract and its inhibitory effect on lipid and protein oxidation of pork patties during chilled storage.

This experiment was conducted to assess the antioxidant efficacy of black currant (Ribes nigrum L.) extract (BCE) in raw pork patties during chilled storage. The extracting conditions of frozen BCE including ethanol concentrations (0-100%) and extracting times (0.25-12h) were studied. BCE extracted with 40% ethanol for 2h had the highest anthocyanin content, the strongest radical scavenging activities as well as the second strongest reducing power. BCE was condensed and added to pork patties at 5, 10 or 20 g/kg. Compared with the control, BCE treatments significantly decreased the thiobarbituric acid-reactive substance values and carbonyls formation and reduced the sulfhydryl loss of pork patties in a dose-dependent manner (P<0.05), which showed that the BCE significantly inhibited lipid and protein oxidation. The BCE-treated patties showed significantly higher redness (P<0.05) than the control. The findings demonstrated strong potential for BCE as a natural antioxidant in meat and meat products.

Antioxidant activity of spice extracts in a liposome system and in cooked pork patties and the possible mode of action.

Three experiments were conducted to assess the antioxidant efficacy of spice extracts in cooked meat. In experiment 1, antioxidant activity of 13 common spice extracts was screened in a liposome system. Six of the extracts (clove, rosemary, cassia bark, liquorice, nutmeg, and round cardamom), identified to have the greatest total phenolic contents, were strongly inhibitory of TBARS formation. In experiment 2, 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing power, and metal chelation of these six spice extracts were evaluated. Clove exhibited the greatest reducing power, and all had strong DPPH scavenging activity. In experiment 3, clove, rosemary, and cassia bark extracts were further tested for in situ antioxidant efficacy. Cooked pork patties containing these spice extracts had markedly reduced TBARS formation and off-flavour scores but a more stable red colour, during storage. The results demonstrated strong potential of spice extracts as natural antioxidants in cooked pork products.

Antimicrobial activity of several herb and spice extracts in culture medium and in vacuum-packaged pork.

Extracts prepared from honeysuckle, Scutellaria, Forsythia suspensa (Thunb), cinnamon, and rosemary with 75% ethanol and from clove oil dissolved in 75% ethanol were applied to inoculated agar media to observe their inhibitory effects on the growth of Escherichia coli, Pseudomonas fluorescens, and Lactobacillus plantarum. All the extracts suppressed the growth of these bacteria; Scutellaria exhibited the strongest effect against E. coli. An orthogonal test revealed that the most effective antimicrobial composite extracts were equal-volume mixtures of 0.125 g/ml Scutellaria + 0.5 g/ml honeysuckle + 0.125 g/ml Forsythia + 0.25 g/ml cinnamon and 0.25 g/ml cinnamon + 0.125 g/ml rosemary + 0.25% clove oil. These mixed extracts also produced strong antimicrobial effects in vacuum-packaged fresh pork, with 1.81- to 2.32-log reductions in microbial counts compared with the control when stored for up to 28 days. The sensory panel detected minimal differences in surface color and off-odors between meat samples treated with herb-spice extracts and the control. These results indicate that combined herb and spice extracts can be used as natural antimicrobials for food preservation.