Effects of lyophilized black carrot (Daucus carota L.) water extract on the shelf life, physico-chemical and microbiological quality of high-oxygen modified atmosphere packaged (HiOx-MAP) ground beef

Properties of encapsulated raspberry powder and its efficacy for improving the pH, colour quality and shelf life of modified atmosphere packaged chicken nuggets

1. Recent research has shown that encapsulated raspberry powder (RP) is a natural colourant for foodstuffs. However, no research has been conducted on its use in chicken nuggets. In addition, the effect of RP on products with and without phosphate addition is unknown. This study assessed the effects of RP (control, 0.5%, 1.0%) and phosphate (0.0%, 0.3%) on the pH and colour quality properties of nuggets.2. In the production of RP, red raspberry (Rubus ideaus L.) juices were encapsulated using maltodextrin in a spray-dryer. Antioxidant activity, total anthocyanin, total phenolics, colour, moisture and pH analyses of the RP were performed.3. Nuggets were packaged in modified atmosphere packaging (MAP; 40%CO2 + 60%N2) and were stored at 2.0 ± 0.5°C for 120 d. The pH and external and internal surface colour (L*, a*, b*, C* and h) values were measured on d 0, 15, 30, 45, 60, 75, 90, 105 and 120 of storage.4. The addition of phosphate increased the pH in the samples, while these decreased with the addition of RP (p < 0.05). During storage, the highest pH were seen in the phosphate samples and the lowest in the nuggets with 1.0% RP addition (p < 0.05).5. With the addition of phosphate, the external surface a* value of nuggets increased (p < 0.05). Depending on the level of RP added to the nuggets, the external surface L* value decreased and a* and b* values increased (p < 0.05). After d 30 of storage, the a* value increased in the samples with RP addition and this increase was higher in the with phosphate nuggets (p < 0.05).6. The internal surface a* value increased with the addition of RP during nugget production (p < 0.05). The increase in a* value was greater in samples with added phosphate (p < 0.05). During storage, the highest a* values were seen in nuggets treated with phosphate + 0.1% RP (p < 0.05). The addition of RP to chicken nugget emulsion improved redness, colour stability and shelf life.

Utilization of spray-dried raspberry powder as a natural additive to improve oxidative stability, microbial quality and overcome the perception of discoloration in vacuum-packed ground beef during chilled storage

The present study was conducted to determine the effects of spray-dried raspberry powder (SDRP) (CONTROL, 1.0%, 2.0%, and 3.0%) as a natural antioxidant, antimicrobial, and colorant on physicochemical properties, lipid oxidation, discoloration, and microbial quality of vacuum-packed (VP) ground beef during chilled storage at 2 ± 0.5 °C for 18 days. By incorporating SDRP into VP ground beef pH, lipid oxidation (TBARS), lightness, and hue angle (h°) values decreased (P < .01), while redness (a*) and chroma (C*) values improved (P < .01). SDRP treatments had higher redness, more stable color, and lower pH and TBARS values during storage in a dose-dependent manner (P < .05), demonstrating that SDRP had a preventive effect on lipid oxidation and discoloration. The combination of vacuum packaging with SDRP generally resulted in lower bacterial growth during storage. These results demonstrated that 2% or 3% SDRP treatment has promising potential as an effective strategy to achieve oxidative and microbial stability and overcome discoloration in VP fresh meats.

Effects of curcumin-mediated photodynamic treatment on lipid degradation of oysters during refrigerated storage

BACKGROUND

Oyster's lipid degradation leads to a decrease in edible and nutritional value. Curcumin-mediated photodynamic treatment (PDT) is an innovative non-thermal technology, although evaluation of the oyster's lipid degradation has been scarce. In the present study, we investigated peroxide value, thiobarbituric acid reactive substance, triacylglycerol and free fatty acids to evaluate the effect of curcumin-mediated PDT on lipid degradation of oysters during refrigerated storage.

RESULTS

The results showed that curcumin-mediated PDT could delay oyster's lipid degradation. Next, the activities of enzymes were detected to determine the mechanisms behind the effects of curcumin-mediated PDT. It was revealed that the activities of lipase, phospholipase A₂ (PLA₂ ), phospholipase C (PLC), phospholipase D (PLD) and lipoxygenase (LOX) were significantly inhibited after curcumin-mediated PDT (P < 0.05). Furthermore, 16 s rRNA analysis established that the relative abundances of Pseudoalteromonas and Psychrilyobacter were reduced by 51.58% and 43.82%, respectively, after curcumin-mediated PDT.

CONCLUSION

Curcumin-mediated PDT could delay oyster's lipid degradation by inhibiting the activities of lipase, PLA₂ , PLC, PLD and LOX, as well as by changing the oyster's microbial composition, reducing the relative abundance of Pseudoalteromonas and Psychrilyobacter. © 2021 Society of Chemical Industry.