Rheological and microstructural properties of beef sausage batter formulated with fish fillet mince

Effect of Palm-Based Shortenings of Various Melting Ranges as Animal Fat Replacers on the Physicochemical Properties and Emulsion Stability of Chicken Meat Emulsion

This study evaluated the effects of palm shortenings (PS) with varying melting ranges (MR) on the physicochemical, emulsion stability, rheological, thermal, textural, and microtextural properties of chicken meat emulsions. Six emulsions were developed: control (chicken skin), sample A (PS at MR of 33-36 °C), sample B (PS at MR of 38-42 °C), sample C (PS at MR of 44-46 °C), sample D (PS at MR of 45-49 °C), and sample E (PS at MR of 55-60 °C). There were no significant differences in cooking loss, pH, and water-holding capacity between the meat emulsions, with sample E providing a more stable emulsion with the lowest fat content and highest moisture content. The colour profiles and protein thermal stabilities of the fat-replaced meat emulsions were not significantly different from the control. The hardness, shear force, storage, and loss moduli increased when palm shortenings with higher melting range were used, with sample E having the highest values. Sample E also exhibited a smaller pore size and more compact structure, and thus was well-emulsified compared to the other samples. Overall, palm shortenings-particularly those with a melting range of 55-60 °C-have the potential to replace chicken skin in meat emulsions.

Evaluation of Pilot-Scale Radio Frequency Heating Uniformity for Beef Sausage Pasteurization Process

Radio frequency (RF) heating has the advantages of a much faster heating rate as well as the great potential for sterilization of food compared to traditional thermal sterilization. A new kettle was designed for sterilization experiments applying RF energy (27.12 MHz, 6 kW). In this research, beef sausages were pasteurized by RF heating alone, the dielectric properties (DPs) of which were determined, and heating uniformity and heating rate were evaluated under different conditions. The results indicate that the DPs of samples were significantly influenced (p < 0.01) by the temperature and frequency. The electrode gap, sample height and NaCl content had significant effects (p < 0.01) on the heating uniformity when using RF energy alone. The best heating uniformity was obtained under an electrode gap of 180 mm, a sample height of 80 mm and NaCl content of 3%. The cold points and hot spots were located at the edge of the upper section and geometric center of the sample, respectively. This study reveals the great potential in solid food for pasteurization using RF energy alone. Future studies should focus on sterilization applying RF energy and SW simultaneously using the newly designed kettle.

Texture and viscoelastic characteristics of silver carp (Hypophthalmichthys molitrix) surimi affected by combination of washing regimes and hydrogen peroxide

This study aimed to apply H₂ O₂ at different concentrations in combination with mince:water (M:W) ratios and different washing cycles (WC) in order to produce surimi gel from silver carp without compromising its quality characteristics. Color, texture, microstructure and rheological properties of surimi gels were investigated. Water holding capacity, texture profile and gel strength, showed a greater dependency on number of washing cycles than the M:W ratios and percentage of H₂ O₂ (p<0.05), i.e., higher washing cycles, firmer surimi gel. Accordingly, T2 (one WC, 2% H₂ O₂ , 1:3), T10 (two WC, 1% H₂ O₂ , 1:2) and T16 (three WC, 1% H₂ O₂ , 1:2) treatments resulted the most cohesive and resilient surimi compared to the rest (p<0.05), confirmed by SEM images. However, all treated fish mince samples with H₂ O₂ , resulted in a surimi gel with lower texture quality compared to the control surimi prepared by conventional washing process without H₂ O₂ (p<0.05). A temperature sweep test was conducted based on the LVR stress and frequency values and the aforementioned surimi gels exhibited an obvious valley shape pattern at temperature range of 48-62°C. In the creep-recovery test, the Burgers model satisfactorily described the internal structure of the surimi gel samples as the lowest deformation belonged to the control samples followed by T2. However, after 300s strain, neither of surimi gels were fully recovered their original shape. Altogether, further studies are needed to clarify the effects of H₂ O₂ in reduction of washing cycles, without significantly affecting the textural and rheological properties of resultant surimi gel.

Olive Leaf Water Extract Protects Chicken Breast Sausages Against Quality Deterioration Induced by Frozen Storage

This study aimed to determine the effect of olive leaf water extract (OEx) on the physical properties of chicken breast sausage (CBS) and the preventive effect of OEx against lipid oxidation in CBS during frozen storage. CBSs, to which 0.1 and 0.5% (w/w) OEx were added to minced meat, were stored frozen at -20°C for 60 days. The thawing weight loss of control CBS without OEx increased with the frozen storage period, while OEx-CBSs did not change, from 15 to 60 days in storage. The water-holding capacity, breaking strength, elasticity, and viscosity of control CBS decreased upon frozen storage, while those of OEx-CBSs did not change. The observation of CBSs using scanning electron microscopy showed that OEx-CBSs that were stored frozen, unlike control CBS, maintained a structure similar to their unfrozen counterparts. These results indicate that OEx confers resistance to CBS upon freezing. Furthermore, the application of OEx to CBS suppressed lipid oxidation, decrease in pH and discoloration induced by frozen storage. Thus, this natural OEx is useful in improving the physical and chemical qualities of frozen processed poultry foods.

Interactions between beef salt-soluble proteins and elephant foot yam (Amorphophallus campanulatus) flour in heat-induced gel matrix development

The objective of this study was to observe the interactions between salt-soluble proteins extracted from beef and elephant foot yam (Amorphophallus campanulatus) flour in heat-induced gel matrix development. The effect of salt concentration; 0.5%, 1.0%, 1.5%, and 2.0% in weight/weight basis (w/w), during protein extraction on pH, salt-soluble protein concentration and myofibril fractions of beef extract was determined firstly, and no significant effect was found. The beef salt-soluble proteins extracted using salt solution at different concentrations were then added with elephant foot yam flour at 5%, 10%, and 15% w/w, gelatinized at 90°C for 20 min, and cooled down at 4°C for 12 h. The interactions between beef salt-soluble proteins and elephant foot yam flour resulted in an improved gel strength (p < 0.01) and the addition level of elephant foot yam flour affected the pH, instrumental color, moisture, crude protein, and ash content significantly. The addition of elephant foot yam flour also reduced the size of the pores in the gel matrix as shown by scanning electron microscope (SEM) photographs. These suggest that elephant foot yam flour well interacts with beef salt-soluble proteins to form gel matrix.