Oil bulking agents based on polysaccharide gels in meat batters: A Raman spectroscopic study

Technological and sensory characteristics of hamburgers made with polyunsaturated gelled emulsions

The quest for healthiness has driven the meat industry to seek solutions to reduce or replace saturated animal fat. The replacement (partial or total) of animal fat by polyunsaturated vegetable oils rich in omega fatty acids has gained prominence in terms of making a product healthier. However, an obstacle to this strategy is the effects on the sensory characteristics of the products, which may be unfavorable to consumers. The objective of this study was to evaluate the lipid reformulation of hamburgers through the total replacement of pork fat with canola, sunflower, and corn oil emulsions. The physical-chemical, technological, and sensory properties analyses were performed. There were no significant changes (P > 0.05) in moisture content, protein content, ash content, pH, weight loss (%), moisture retention (%), or shrinkage (%). However, the lipid content was reduced (P < 0.05) and there was a significant improvement in the fatty acid profile with the application of gelled emulsions. The lipid peroxidation and oxidation also increased (P < 0.05) for the samples with the addition of gelled emulsions, and we observed the same behavior for lipid retention (%). In the sensory evaluation, the samples showed good overall acceptance, with hedonic scores ranging from "like slightly" to "like very much." In addition, through check-all-that-apply questions, we observed that the most positive scores given applied to the treatments were applied to the emulsions. The total replacement of animal fat by gelled emulsions is a promising strategy for producing healthier hamburgers.

Insight into the Mechanism of Porcine Myofibrillar Protein Gel Properties Modulated by κ-Carrageenan

The purpose of this study is to explain the mechanism of porcine myofibrillar protein gel properties modulated by κ-carrageenan. The textural properties results showed that the stress at fracture of the composite gel with 0.4% κ-carrageenan had the highest value (91.33 g), which suggested that the 0.4% κ-carrageenan addition was the limitation. The strain at fracture was significantly reduced with κ-carrageenan addition. The composite gel with 0.4% κ-carrageenan had the lowest proportion of T22 (7.85%) and the shortest T21 relaxation time (252.81 ms). The paraffin section showed that the phase separation behavior of the composite gel transformed from single-phase behavior to dispersed phase behavior to bi-continuous phase behavior, and the ratio of CG/MP phase area significantly increased from 0.06 to 1.73. The SEM showed that the three-dimensional network of myofibrillar protein transformed from a loose structure to a compact structure to an unaggregated structure with κ-carrageenan addition. The myofibrillar protein network of the treatment with 0.4% κ-carrageenan had the highest DF value (1.7858) and lowest lacunary value (0.452). The principal component analysis was performed on the data of microstructure and textural properties, and the results showed that the dispersed phase behavior and moisture stabilization promoted the aggregation of myofibrillar protein and the composite gel had better water holding capacity and textural properties, while bi-continuous phase behavior hindered the aggregation of myofibrillar protein and the composite gel had worse water holding capacity and textural properties.

Comparison of High Hydrostatic Pressure Processed Plus Sous-Vide Cooked Meat-Based, Plant-Based and Hybrid Patties According to Fat Replacement

The impact of high-pressure processing (HPP) alone and combined with sous-vide cooking (SVCOOK) on the physicochemical and sensory traits of patties from different fat and protein matrices was evaluated. Hydro-gelled and soya emulsions were tested in meat (M), hybrid (H) and plant-based (P) patties (six formulations). M patties with pork backfat were used as reference formulation. All samples were pressurized (350 MPa, 10 min) and the HPP + SVCOOK patties were subsequently vacuum-cooked (55 °C). Significant changes (p < 0.05) in physicochemical parameters were detected in HPP and HPP + SVCOOK samples. Hardness reached the maximum value (11.0 N) in HPP treated P patties with soya emulsion. The HPP + SVCOOK M patties with backfat recorded the highest hardness (29.9 N). Irrespective of the fat formulations, the sensory characteristics of the HPP and HPP + SVCOOK M patties showed a well differentiated profile compared to H and P patties. The highest intensities for fatness, flavor, chewiness and the lowest for friability were recorded in HPP + SVCOOK M patties with backfat. The differences in physicochemical and sensory parameters of HPP + SVCOOK patties were minimal. Successful fat replacement using either one of the soya or hydro-gelled emulsion could be conducted in HPP + SVCOOK patties.

Enhancing gelling properties of high internal phase emulsion-filled chicken gels: Effect of droplet fractions and salts

Effects of high internal phase emulsion (HIPE) stabilized by egg yolk-modified starch complex on the gelling properties of chicken gels with or without sodium chloride (NaCl)/sodium tripolyphosphate (TP) were studied. The addition of 30 % HIPE increased the hardness from 376 g to 590 g. The NaCl addition further improved textural and viscoelastic properties compared with the gels without NaCl. 30 % HIPE-filled gels with salts (NaCl and TP) has the highest hardness (3562 g) and the lowest cooking loss (3.41 %). Fourier transform infrared spectra (FTIR) revealed that salts, especially TP, could promote the transition of α-helices to β-sheets structure. Moreover, the chicken gels with TP had higher acyl chain disorder. In summary, the co-addition of HIPE and salt (NaCl/TP) has a positive effect on the formation of chicken gel, thereby providing potential applications in comminuted meat products.

Encapsulation of Satureja khuzistanica jamzad essential oil in chitosan nanoparticles with enhanced antibacterial and anticancer activities

Satureja khuzistanica jamzad (SKJ), which is a member of Lamiaceae, has various proven effects such as antispasmodic and anti-inflammatory, anti-diabetic, antioxidant, and antifungal properties. However, the use of essential oil of plants is limited due to their inherent instability in the environment. Encapsulation with nanoparticles in the nanogel forms is one of their stabilization methods. The aim of this study was to synthesize nano-gel based on chitosan (CS) and extracts of SKJ essential oil, and to evaluate the antibacterial and anticancer activities. SKJ essential oil was extracted using water distillation method. Then, it was loaded on CS particles using two-step process as following: droplets formation and freezing. The Dynamic Light Scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Zeta potential determination were used to evaluate the physical and chemical properties of CS-SKJ nanogel, which its result was acceptable. After confirmation of the loaded essential oil rate and releasing amount, the antibacterial effects were evaluated on five Gram-positive bacteria and five Gram-negative bacteria using microbroth dilution method. The encapsulation efficiency, size, polydispersity index, and zeta potential of nanoparticles were characterized were 30.74%, 571.00 nm, 0.451 and -67.2 mV, respectively. The results were significant not only on Gram-positive bacteria, but also on Gram-negative bacteria. The MIC range was between 7.8 and 500 µg/ml. The CS-SKJ nanogel has acceptable anticancer activities on KB and A549 tumor cell lines. the IC50 range was between 5.6 and 6.71 µg/ml. The results indicate that both CS particles and SKJ alone, and CS-SKJ nanogel could be considered as the outlook to produce new antimicrobial and anticancer drugs.

Insight into the mechanism of myofibrillar protein gel influenced by konjac glucomannan: Moisture stability and phase separation behavior

The effect and mechanism of myofibrillar protein (MP) gelation influenced by konjac glucomannan (KG) addition were studied. The KG addition significantly improved gel strength and water holding capability (WHC) of MP-KG composite gel, but it had additive limitation at 1.0%. The SEM showed that KG (<1.0%) reduced the appearance of moisture channels and promoted the formation of an integral MP gel network. Raman spectroscopy showed that KG addition (<1.0%) promoted the protein unfolding and the interaction of hydrophobic groups during thermal processing. However, the KG (>1.0%) would form continuous viscous hydrogel and interpenetrate with the MP solution, which hindered the interaction of hydrophobic groups during thermal process, and the MP formed a loose and degraded final structure. Hence, MP gels produced with the addition of KG underwent a transformation from a loose structure to a compact structure to an unaggregated structure, which was influenced by moisture stability and phase separation behavior.

Advances in our understanding of the structure and functionality of edible fats and fat mimetics

The reasons for the increased world-wide incidence of obesity, type-2 diabetes, and cardiovascular disease include sedentary lifestyles and poor food choices. Regulatory agencies in several countries now require companies to add unattractive front of package labels to their products where salt, sugar and fat (or saturated fat) levels are prominently displayed. After the demise of partially hydrogenated fats, saturated fat has become the new target. Consumption of saturated fat over polyunsaturated oil has been clearly shown to increase cholesterol levels in humans. However, saturated fats provide the functionality required in many food products. To complicate matters, concerns over sustainability, veganism, genetically modified organisms, animal welfare, as well as religious beliefs, severely limit our sources of saturated fat. In this review we will discuss recent advances in our understanding of the nano and mesoscale structure of fats, responsible for their physical functionality and contrast it to that of fat mimetics. Fat mimetics include polymeric networks of ethylcellulose, emulsion-templated networks of proteins and polysaccharides, colloidal and self-assembled fibrillar networks of polar lipid crystals, as well as solid o/w emulsions of oil trapped within crystallized lamellar mesophases. Clean label and economic considerations will also be touched upon.

Chia and oat emulsion gels as new animal fat replacers and healthy bioactive sources in fresh sausage formulation

This paper examines the effect of emulsion gels (EG) prepared with chia (CEG) and oats (OEG) used as animal fat replacers in reduced-fat fresh sausages (longaniza) (LRF) during chilled storage. Reduced-fat samples were reformulated with CEG and OEG, (LRF/CEG and LRF/OEG respectively). Normal (LNF/P) and reduced-fat (LRF/P) (all-pork-fat) sausages were used as controls. Nutritional composition and microbiological, technological and sensory characteristics of sausages were evaluated. The presence of an EG affected (P<0.05) the concentrations of some minerals and amino acids in sausages. CEG improved MUFA and PUFA contents. Cooking loss was lower (P<0.05) in LRF/CEG and LRF/OEG than in the controls. Of all the reduced-fat samples, Kramer shear force values (KSF) were highest (P<0.05) in the ones containing an EG. KSF generally increased (P<0.05) over storage in all samples. The microbial count was significantly affected by the use of CEG. Sensory properties were affected by the incorporation of an EG, but all sausages were judged acceptable.

Edible oil structuring: an overview and recent updates

In recent years, research dealing with edible oil structuring has received considerable interest from scientific community working in the area of food formulation. Much of this interest is linked to the possibility of using structured oil in development of newer product formats with improved nutritional profile (trans fat-free, low in saturated fats and high in mono and/or poly unsaturated fatty acids). In addition to the obvious industrial need of finding the alternative formulation approach, the interesting properties of structured systems (particularly, oleogels) also makes them a fascinating subject for fundamental studies. In this paper, we attempt to give a comprehensive and concise overview of the field of oil structuring with special emphasis on the updates from recent years. Specifically, several categories of food-grade oleogelators and their potential food applications are summarized with typical examples along with a discussion on the general principles and unresolved challenges related to this emerging area.

Effects of emulsion gels containing bioactive compounds on sensorial, technological, and structural properties of frankfurters

Emulsion gels prepared with olive oil, chia, and cold gelling agents (transglutaminase, alginate, or gelatin) were used as fat replacers in reduced-fat frankfurter formulation. Nutritional advantages, sensory analysis, technological properties, and microbiological populations of frankfurters were evaluated along with their lipid structural characteristics over chilled storage. Frankfurters with emulsion gels showed significant improvements in fat content (lower saturated fatty acid, higher mono- and polyunsaturated fatty acid contents) and had good fat and water-binding properties. The presence of an emulsion gel reduced lightness and redness, but increased yellowness. Textural behavior of samples was significantly affected by the presence of emulsion gels and by storage. Sensory properties were not affected by the incorporation of emulsion gels, and all frankfurters were judged acceptable. Attenuated total reflectance–Fourier transform infrared spectroscopy results showed that samples with emulsion gels involve more lipid–protein interactions. Frankfurters with emulsion gels showed good stability to oxidation during storage and contained lower levels of microorganism than reduced-fat control at 85 days.

Raman spectroscopic study of structural changes upon chilling storage of frankfurters containing olive oil bulking agents as fat replacers

Technological properties and structural characteristics of proteins and lipids, using Raman spectroscopy, of frankfurters formulated with olive oil bulking agents as animal fat replacers were examined during chilling storage. Frankfurters reformulated with oil bulking agents showed lower (P<0.05) processing loss and higher (P<0.05) hardness and chewiness. Purge loss during chilling storage was relatively low, demonstrating a good water retention in the products. β-Sheet structures were enhanced by the use of olive oil bulking agents, and this effect was more pronounced in samples containing inulin. Reformulated frankfurters contained the least turns (P<0.05). A significant decrease of β-sheets and an increase of turns were observed after 85 days of chilled storage. The lowest (P<0.05) values of IνsCH2/IνasCH2 were recorded in frankfurters reformulated with oil bulking agents, which suggests more lipid acyl chain disorder. Structural characteristics were correlated to processing losses, hardness, and chewiness.