Incorporation of hydrogen-producing magnesium into minced beef meat protects the quality attributes and safety of the product during cold storage.

The impact of hydrogen (H2) producing magnesium (Mg) incorporation into minced beef meat (MBM) on the quality and safety of the product was investigated. The H2-producing Mg (H2-P-Mg)-incorporated MBMs were vacuumed (VP) and stored at 4 °C for 12 days. Other MBMs were vacuumed and gassed with H2 or N2. At the end of storage, the lowest browning index values were for H2 and H2-P-Mg samples. H2- PMg and VP methods generally decreased the counts of mesophilic and psychrotrophic bacteria and yeast molds and restricted the formation of thiobarbituric acid reactive substances and biogenic amines. Heat mapping, PCA, and multivariate analysis methods confirmed chemical analysis results. The volatile compounds were at their highest levels in the control samples at the end of storage, followed by H2, N2, H2-P-Mg, and VP samples. Using the H2-P-Mg method in MBM preparation could protect the quality characteristics and safety of the product during cold storage.

Antioxidant, anticholinesterase and antibacterial activities of Stachys guyoniana and Mentha aquatica.

CONTEXT: Stachys guyoniana Noë ex. Batt. and Mentha aquatica L. are two Algerian Lamiaceae used in folk medicine. OBJECTIVE: To investigate their antioxidant, anticholinesterase and antibacterial activities. MATERIAL AND METHODS: n-Butanol (BESG), ethyl acetate (EESG) and chloroform (CESG) extracts of S. guyoniana and methanol (MEMA) and chloroform (CEMA) aerial part extracts of M. aquatica and methanol (MERMA) and acetone (AERMA) roots extracts of M. aquatica were evaluated for their antioxidant activity by the ß-carotene-linoleic acid, DPPH• and ABTS•+ scavenging, CUPRAC and metal chelating assays. The anticholinesterase activity was tested against AChE and BChE. The antibacterial activity was assessed by MICs determination against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella heidelberg, Klebsiella pneumoniae, Enterobacter aerogenes and Morganella morganii strains. RESULTS: In the ß-carotene test, the CESG (IC50: 2.3 ± 1.27 µg/mL) exhibited the highest activity. The BESG was the best scavenger of DPPH• (IC50: 2.91 ± 0.14 µg/mL). In the ABTS test, AERMA was the most active (IC50: 4.21 ± 0.28 µg/mL). However, with the CUPRAC, the BESG exhibited the best activity (A0.50: 0.15 ± 0.05 µg/mL) and was active in metal chelating assay with 48% inhibition at 100 µg/mL. The BESG was the best AChE inhibitor (IC50: 5.78 ± 0.01 µg/mL) however, the AERMA showed the highest BChE inhibitory activity (IC50: 19.23 ± 1.42 µg/mL). The tested extracts exhibited a good antibacterial activity. CONCLUSION: This study demonstrated good antioxidant, anticholinesterase and antibacterial potential of S. guyoniana and M. aquatica, which fits in well with their use in folk medicine.