Degradation of meat quality has always been a burning issue in fish preservation. To maintain the quality, a novel combination of chlorogenic acid (CGA) and chitosan (CS) coating was applied to snakehead fish fillets. Fish fillets were soaked into 2% chitosan (2CS), 0.2% CGA in 2% chitosan (0.2CGA/2CS), 0.5% CGA in 2% chitosan (0.5CGA/2CS), or 1.0% CGA in 2% chitosan (1.0CGA/2CS) solution; and then, coated samples were vacuum‐packaged and stored at 2 ± 0.5°C. pH values, color values, microbial loads, hardness, sensory qualities, and oxidization of lipids and proteins of stored fish fillets were investigated for 5 months. Antimicrobial activity was found to be nonsignificant (p ≤ .05) among different coated fish fillets, while color, antioxidant, and pH values were significantly (p ≤ .05) different. Lipid oxidation and protein oxidation were found to be inhibited in 2CS‐, 0.5CGA/2CS‐ and 1.0CGA/2CS‐coated fish fillet. All CGA/CS coating delayed increase in pH (p ≤ .05) and resulted brown color. However, only CS coating resulted in higher sensory scores (p ≤ .05) and controlled browning. Considering antioxidant properties and other quality parameters, CGA/CS coating might be applied commercially in fish preservation.
To explore the physicochemical characters of barley grass, ultra‐micro‐crushing (UMC) technology combined with air drying or freeze drying was carried out. After barley grass was air‐dried at 70°C or freeze‐dried at 15°C, it was grinded for 30, 60, 90, and 120 min using UMC, respectively. After combined processing, moisture content, particle size, odor, color, microstructure, water and oil‐holding capacity, the content of flavonoid and chlorophyll, water activity, and sensory qualities were determined. The particle size of barley grass powder decreased, and lightness value was increased; water and oil‐holding capacity decreased significantly (p ≤ .05), whereas swelling and dissolving capacity increased in the processed grass powder. On the other hand, the total flavonoid content increased significantly (p ≤ .05). Barley grass odor features sulfide aroma, and its microstructure demonstrates lamellar morphology with some fewer fragmented pieces. The results suggested combined UMC at 90–120 min will be suitable for processing barley grass powder.
1 January 2020 in International Journal of Food Properties
To prevent the degradation, snakehead fish fillets were infiltrated in 4% chlorogenic acid solution for 10, 20, and 30 min; which correspond to chlorogenic acid concentration of 0.2%, 0.5%, 0.7% in the infiltrated samples, respectively. Treated fish fillets were then stored at 2 ± 0.5°C for 2 weeks and were evaluated for total volatile base nitrogen (TVB-N), trimethylamine (TMA), pH, acid value (AV), peroxide value (POV), total bacterial count, and sensory qualities. Results advocated that chlorogenic acid penetration inactivated about 2-log CFU/g microorganism, while TVB-N and TMA were limited to about 10 mg/100 g. Rising kinetics of pH, AV, and POV were impeded markedly as well as 2 weeks of acceptable storage was achieved. Chlorogenic acid penetration features promotion of fish quality, decrease of microbial load and textures. This novel treatment can be applied industrially in tenderization of meat, storage of meat, and microbial inhibition of meat during preservation.
To examine the processing characteristics and high quality of an improved microwave vacuum drying system, litchi fruits were dried using intermittent microwave volumetric heating while microwave vacuum drying at 2 W/g was carried out for comparison; the intermittent microwave heating profiles were set as (1) 5 min drying-on, 5 min drying-off; (2) 5 min drying-on, 10 min drying-off; and (3) 5 min drying-on, 15 min drying-off. Energy consumption during drying was determined, and physicochemical properties such as moisture content, vitamin C, total phenolics, color, and sensory evaluation of dried products were assessed. In microwave vacuum drying, intermittent microwave volumetric heating was found to be energy-efficient (about 32 KJ/g to 45 KJ/g) and saved at least 31% of energy consumption compared with microwave vacuum drying as well as decreasing product browning. In addition, microwave volumetric heating had no substantial effects on sugar and protein contents, while antioxidants were affected significantly (p ≤ 0.05). Moreover, sensory evaluation showed that intermittent microwave-assisted vacuum drying (IMVD) increased the acceptance of the dried product compared with microwave vacuum drying (MVD).