Effect of ethanolic extract from Morus alba L. leaves on the quality and sensory aspects of chilled pork under retail conditions.

The aim of this study was to investigate the performance of ethanolic extract from Morus alba L. leaves (MLEE) in preserving chilled pork under retail conditions. The four treatments were 5 mg/mL sodium benzoate solution (SB), 1 mg/mL MLEE solution (high-concentration MLEE; HM), 0.5 mg/mL MLEE solution (low-concentration MLEE; LM), and 0 mg/mL MLEE solution (C). The quality characteristics, pH, thiobarbituric acid reactive substances values, metmyoglobin, total volatile basic nitrogen, and number of microbes of MLEE-treated chilled pork stored at 4 °C for 9 days were consistent with those obtained by the SB treatment and lower than those obtained by the C treatment. Sensory analyses showed that treatment of pork with MLEE did not have a negative impact on its sensory characteristics. MLEE can extend the shelf life of chilled pork from 3 days to 6 days (9 days) in first-class (second-class) fresh meat. Results suggest that MLEE could be a candidate resource in the preservation of chilled pork.

Flavonoids from Morus alba L. Leaves: Optimization of Extraction by Response Surface Methodology and Comprehensive Evaluation of Their Antioxidant, Antimicrobial, and Inhibition of α-Amylase Activities through Analytical Hierarchy Process.

To explore the flavonoids from Morus alba L. leaves (MLF), the process of extracting was optimized by a response surface methodology and the antimicrobial and antioxidant activities were evaluated in vitro. The yield of flavonoids reached 50.52 mg g-1 under the optimized extraction conditions (i.e., extraction temperature, 70.85 °C; solvent concentration, 39.30%; extraction time, 120.18 min; and liquid/solid ratio, 34.60:1). The total flavonoids were extracted in organic solvents with various polarities, including petroleum ether (MLFp), ethyl acetate (MLFe), and n-butanol (MLFb). In vitro, the four MLF samples exhibited good antioxidant activities for scavenging of 2, 2'-azinobis-(3-ethylbenz-thiazoline-6-sulphonate) radical, 1, 1-diphenyl-2-picrylhydrazyl radical, and total reducing power. Regarding antimicrobial efficacy, the MLF samples suppressed the development of Staphylococcus aureus, Bacillus subtilis, and Bacillus pumilus. The MLF samples inhibited α-amylase activity to a certain extent. The analytical hierarchy process (AHP) was used to evaluate comprehensively the bioactivities of the MLF samples. The AHP results revealed that the bioactivity comprehensive score (78.83 µg mL-1) of MLFe was optimal among the four MLF samples. Morus alba L. leaves also exhibited non-hemolytic properties. All bioactivities suggested the potential of MLFe as a candidate resource in the food and drug industries.