Effects of ultrasound-assisted curing on the quality and microstructure of low-sodium beef jerky

Influence of Capsicum chinense concentration and salt varieties on the quality attributes of Kilishi, a sundried beef jerky

The impact of Capsicum chinense concentration and salt varieties on cholesterol oxides, physicochemical properties, microbial profiles and organoleptic attributes of Kilishi, a sundried beef jerky, was assessed. Kilishi (KL) was prepared from sundried strips of Biceps femoris and marinated with either 2 % Sodium chloride (NaCl) + 7 % fresh Capsicum chinense (CC) (KL-1), 1 % NaCl + 1 % Potassium chloride (KCl) + 7 % CC (KL-2), 1 % NaCl + 1 % Potassium citrate (C6H5K3O7) + 7 % CC (KL-3), 1 % NaCl + 14 % CC (KL-4), 1 % KCl + 14 % CC (KL-5) or 1 % C6H5K3O7 + 14 % CC (KL-6), and stored at 29 ± 1 °C for 90 d. The partial or total replacement of NaCl lowered (P < 0.05) the Na content in KL. The KL samples treated with 14 % CC had lower (P < 0.05) 25-hydroxy cholesterol, cholesta-3,5-dien-7-one, carbonyl, pH, malondialdehyde, and lightness and greater (P < 0.05) redness and Lactobacillus counts than those treated with 7 % CC. The chemical composition, sensory scores and water activity were unaffected by the additives. The taste, flavor, and overall acceptance scores of KL decreased (P < 0.05) after 30 days of storage. The substitution of KCl and C6H5K3O7 for NaCl and the increase in CC concentration from 7 to 14 % lowered the Na content and selected cholesterol oxides, respectively, without impairing the organoleptic traits of Kilishi.

Magnetic fields improve the gel properties of myofibrillar proteins in low-salt myofibrillar protein emulsion systems

The effect of magnetic field on the properties of emulsified gels containing myofibrillar protein (MP-emulsified gels) with different salt concentration (0, 0.2, 0.4, 0.6 mol/L) were investigated. The results demonstrated that the magnetic field treatment (4 °C, 3.8 mT, 3 h) made the emulsion droplets smaller and more uniform. At the same time, the magnetic field treatment improved the gel strength and WHC (water holding capacity) of MP-emulsified gels by 88.89 % and 3.5 % at 0.2 mol/L NaCl, and it also ameliorated the network structure of emulsified gel. Raman spectra showed that magnetic field treatment induced the transformation of β-structure into α-helix structure in MP-emulsified gel. Under high salt conditions (0.4 mol/L ∼ 0.6 mol/L), the magnetic field promoted the exposure of aliphatic residues in the tertiary structure and influences the hydrophobic interaction between molecules. In conclusion, Magnetic field treatment (4 °C, 3.8 mT, 3 h) improved MP-emulsified gels properties, offering a promising strategy for low-salt meat products.

Ultrasound-assisted low-sodium salt curing to modify the quality characteristics of beef for aging

Meat products for elderly people are high in sodium content and hardness. Thus, the aim of this study is to explore how ultrasound-assisted low-sodium salting improves meat quality and determine the conditions that result in meat tenderness ideal for people aged 65-74 years. The ultrasound-assisted treatment of bovine hip muscle with non-sodium salt (CaCl2 and C6H10CaO6) was adopted, followed by sous vide (SV) cooking (65 ℃ for 8-12 h). Results showed that ultrasound-assisted low-sodium salt curing can considerably reduce the shear force and hardness of beef (P < 0.05), promote the diffusion of Na+ (P < 0.05), and increase water content (P < 0.05), consistent with the water mobility results of low-field nuclear magnetic resonance. The tenderized effects were examined by Raman spectroscopy, which showed that the ordered α-helix and β-fold contents of the meat proteins decreased, and disordered β-turn and random coil contents increased after heat treatment with ultrasound-assisted low-sodium salt curing. Scanning electron microscopy revealed that the degree of muscle fiber destruction by ultrasound-assisted low-sodium salt curing combined with heat treatment was higher than that observed after traditional cooking with high amounts of sodium. With regard to tenderness, beef marinated with ultrasound-assisted C6H10CaO6 and subjected for 10 h was preferred by people aged 65-74 years. Ultrasound-assisted low-sodium salt curing can improvements on simultaneously reduce the sodium content and enhance the tenderness of meat products for elderly people, and provides an ultrasonic scheme for meat processing using non-sodium salt.

Ultrasound effect on flavor profile of beef jerky produced with partial potassium salt substitute based on GC-IMS technology

Traditional beef jerky contains a high content of sodium salt while the reduction of sodium usage impairs the flavor of final product. Regarding above issues, this research innovatively applied ultrasound-assisted salts (NaCl and KCl) recombination in the pickling stage of low-sodium beef jerky, and further compared the flavor differences caused by ultrasound by sensory evaluation, E-nose and GC-IMS. Besides, the changes of physicochemical qualities were explored including salts content, color and shear force. Results showed that ultrasound had positive impacts on flavor quality. The 400 W treatment was chosen as an optimal group for flavor improvement which was mainly related with the increased level of 5 aldehydes (nonanal, 3-methylbutanal, heptanal, pentanal and octanal) and the decreased level of 3 ketones (2-butanone, 2-pentanone and 2,3-pentanedione). Simultaneously, ultrasound increased the redness and tenderness of final product. Thus, ultrasound is a promising approach for improving the flavor of low-sodium beef jerky.

Improving Structural, Physical, and Sensitive Properties of Sodium Alginate-Purple Sweet Potato Peel Extracts Indicator Films by Varying Drying Temperature

Sodium alginate (SA)-purple sweet potato peel extracts (PPE) from industrial waste indicator films were developed at different drying temperatures (25, 30, 35, 40, 45, 50, and 55 °C). The effects of drying temperatures on the film's structural, physical, and sensitive properties were investigated. On the structural properties, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction indicated that compactness, intermolecular interactions, and crystallinity of indicator films were improved at a lower drying temperature. On the physical properties, with the drying temperature increasing, elongation at the break increased significantly (p < 0.05); ΔE and water-vapor permeability decreased significantly (p < 0.05); and thickness and tensile strength initially increased significantly (90.46 → 98.46, 62.99 → 95.73) and subsequently decreased significantly (98.46 → 71.93, 95.73 → 55.44) (p < 0.05), with the maximum values obtained at 30 °C. On sensitivity, the corresponding colors of the films became lighter as the drying temperature increased, and the films exhibited relatively excellent pH and NH3 sensitivity, with easily discernible color changes at lower temperatures. The results of this paper revealed that the overall film characteristics are improved at lower drying temperatures, which will provide valuable references for selecting the drying temperature for preparing indicator films as a guide for industrialized production.

Effect of ultrasound treatment on porcine myofibrillar protein binding furan flavor compounds at different salt concentrations

The effects of ultrasound (500 W) on the interaction of porcine myofibrillar protein (MP) with furan flavor compounds at different salt concentrations (0.6 %, 1.2 % and 2.4 %) were investigated. With the increase of salt concentration, the particle size of MP decreased, and the surface hydrophobicity and active sulfhydryl content increased due to the unfolding and depolymerization of MP. At the same time, ultrasound promoted the exposure of hydrophobic binding sites and hydrogen bonding sites of MP in different salt concentration systems, thus improving the binding ability of MP with furan compounds by 2 % to 22 %, among which MP had the strongest binding capacity of 2-pentylfuran. In conclusion, ultrasound could effectively promote the unfolding of the secondary structure of MP, which was beneficial to the combination of MP and furan flavor compounds under different salt concentrations.