As a natural potential resource, Tamarix ramosissima has been widely used as barbecue skewers for a good taste and unique flavor. The polyphenolics in the branch bark play a key role in the quality improvement. The purposes of the present work were to explore the polyphenolic composition of T. ramosissima bark extract and assess their potential antioxidant and antimicrobial activities. Hispidulin and cirsimaritin from T. ramosissima bark extract were first identified in the Tamarix genus reported with UPLC-MS analysis. Isorhamnetin (36.91 μg/mg extract), hispidulin (28.79 μg/mg extract) and cirsimaritin (13.35 μg/mg extract) are rich in the bark extract. The extract exhibited promising antioxidant activity with IC50 values of 117.05 μg/mL for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 151.57 μg/mL for hydroxyl radical scavenging activities, as well as excellent reducing power with an EC50 of 93.77 μg/mL. The bark extract showed appreciable antibacterial properties against foodborne pathogens. Listeria monocytogenes was the most sensitive microorganism with the lowest minimum inhibitory concentration (MIC) value of 5 mg/mL and minimum bactericidal concentration (MBC) value of 10 mg/mL followed by S. castellani and S. aureus among the tested bacteria. The T. ramosissima bark extract showed significantly stronger inhibitory activity against Gram-positive than Gram-negative bacteria. Nevertheless, this extract failed to show any activity against tested fungi. Overall, these results suggested that T. ramosissima shows potential in improving food quality due to its highly efficacious antioxidant and antibacterial properties.
Free radicals are ubiquitous in roasted foods. In this work, lipid-derived carbon-centered alkyl radical formation was first studied in roasted meat by electron spin resonance (ESR). The influence of antioxidants on the inhibition of free radicals was investigated. The results showed that the high temperature, high heat transfer rate, and high polyunsaturated fatty acid (PUFA) content resulted in high radical content in roasted meat, while the high water content in meat retarded radical formation. The 0.03% addition of tea polyphenols (TPP) significantly reduced radical formation during roasting (p < 0.05), whereas the 0.03% rosemary extract (RE) had no significant inhibitory effect (p > 0.05). These results suggested that water retention and the addition of TPP would decrease radical generation during the roasting of meat.
Tamarix has been widely used as barbecue skewers to obtain a good taste and a unique flavor of roast lamb in China. Many flavonoids have been identified from Tamarix, which is an important strategy employed to reduce the formation of heterocyclic amines (HAs) in roast meat. Isorhamnetin, hispidulin, and cirsimaritin from Tamarix ramosissima bark extract (TRE) effectively inhibit the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP), the most abundant HAs in foods, both in roast lamb patties and in chemical models. According to the results of the GC-MS analysis, TRE and the three flavonoids significantly reduced the contents of phenylacetaldehyde, an important intermediate involved in PhIP formation at three levels. A subsequent ultra performance liquid chromatography-mass spectrometry (UPLC-MS) analysis revealed that these flavonoids trapped phenylacetaldehyde by forming interaction adducts. The formation of three postulated adducts, 8-C-(E-phenylethenyl)isorhamnetin, 6-C-(E-phenylethenyl)isorhamnetin and 8-C-(E-phenylethenyl)hispidulin, in the chemical models and roast lamb patties was further confirmed by a TOF-MS/MS analysis. Our results demonstrate that TRE and the corresponding flavonoids trap phenylacetaldehyde to form adducts and thus inhibit PhIP formation, suggesting their great potential beneficial effects on human health.
In this study, we investigated the effects of soybean oil, water, and 1, 2, and 3% eggplant powder (EP) as substitutes for pork back fat (a decrease from 30% to 15%) on the proximate composition, water- and fat-binding properties, colour, water distribution, texture, and sensory properties of pork sausages. The replacement of fat with soybean oil in sausages decreased the fat and cholesterol proportions and increased the moisture content, but the water- and fat-binding properties, texture properties, and sensory properties became worse. By adding EP, sausages displayed remarkably better water- and fat-binding properties, texture properties, and sensory properties. Moreover, EP addition significantly accelerated T2 relaxation time, increased the immobilised water content, and decreased the free water content of sausages. Sausages with 2% EP had the highest flavour, mouthfeel, and overall acceptability. This work provides theoretical and data support for the preparation of sausages with EP rich in unsaturated fatty acids (UFAs) and dietary fibre.
The present study was conducted to explore the impact of novel water–oil mixed frying and traditional oil frying methods on the soybean oil quality and formation of trans fatty acids (TFAs) and heterocyclic amines (HCAs) in fried duck breast and skin during 60 frying cycles. The acid value of the soybean oil was 2.10 mg/g using the traditional oil frying and 1.08 mg/g using water–oil mixed frying at the 60th frying cycle. The peroxide value of the water–oil mixed fried soybean oil was significantly lower than that of the traditional frying method. Water–oil mixed frying delayed the formation of TFAs in the soybean oil. The traditionally oil fried skin showed increased TFAs (9tC16:1) content from 0.17 to 0.22 mg/g (29.4% increase), while those of the water–oil mixed fried samples increased from 0.16 to 0.20 mg/g (25.00% increase) compared to control. Harman, Norharman and AαC were detected in all the fried samples and PhIP was observed after the 20th frying cycle, while MeAαC was formed only at the 60th frying cycle in traditional fried duck breast. Therefore, it is concluded that the water–oil mixed frying method is more suitable to improve the quality and safety of fried duck skin and breast meat.
The goal of the investigation was to study the protective effects of the SWGEDWGEIW (the single peptide, TSP) from soybean peptides (SBP) on hydrogen peroxide (H2O2)-induced apoptosis together with mitochondrial dysfunction in PC-12 cells and their possible implications to protection mechanism. Meanwhile, the SBP was used as a control experiment. The results suggested that SBP and TSP significantly (p < 0.05) inhibited cellular oxidative damage and ROS-mediated apoptosis. In addition, SBP and TSP also enhanced multiple mitochondrial biological activities, decreased mitochondrial ROS levels, amplified mitochondrial respiration, increased cellular maximal respiration, spare respiration capacity, and ATP production. In addition, SBP and TSP significantly (p < 0.05) raised the SIRT3 protein expression and the downstream functional gene FOXO3a. In the above activity tests, the activity of TSP was slightly higher than that of SBP. Taken together, our findings suggested that SBP and TSP can be used as promising nutrients for oxidative damage reduction in neurons, and TSP is more effective than SBP. Therefore, TSP has the potential to replace SBP and reduce neuronal oxidative damage.