Antibacterial activity and sensory properties of Heracleum persicum essential oil, nisin, and Lactobacillus acidophilus against Listeria monocytogenes in cheese.

AIM: The aim of this study was to evaluate the antibacterial and chemical effect of Heracleum persicum essential oil (EO), nisin, Lactobacillus acidophilus, and their combination against Listeria monocytogenes both in vitro and in Iranian white cheese model. MATERIALS AND METHODS: Chemical compositions of H. persicum EO were analyzed by gas chromatography-mass spectrometry. After production of Iranian white cheese, minimum inhibitory concentration (MIC) and minimum bactericidal concentration of EO and nisin and agar spot test of L. acidophilus against L. monocytogenes were evaluated. RESULTS: Hexyl butanoate (25.98%), octyl isobutyrate (17.82%), methyl butyrate (14.37%), and pentyl cyclopropane (12.77%) were the main components of the EO. MIC of the EO against L. monocytogenes was 2.5 mg/mL. Combination of nisin (5.3 IU/mL) and H. persicum EO (2500 µg/mL) showed increasing effect against L. monocytogenes (fractional inhibitory concentration = 0.9), while a higher concentration of EO and nisin showed undesirable effect on the cheese flavor. Furthermore, a combination of 1012 CFU/g L. acidophilus with H. persicum EO at the concentration of 2.5 mg/mL (T12) showed acceptable sensorial and also antibacterial results in Iranian white cheese. CONCLUSION: Combination of H. persicum EO, L. acidophilus, and nisin can be recommended as natural preservatives and flavoring agents in cheese.

Hyperoside and anthocyanin content of ten different pomegranate cultivars.

Pomegranate (Punica granatum L.) is native to the Mediterranean region and has been used extensively as a medicine in many counties. Hyperoside is known as an important flavonoid with antioxidant activity and anti hypertension effect. Anthocyanins are the active component in several herbal medicines, thus accurate measurement of hyperoside and anthocyanins, along with their degradation indices, is very useful to food technologists and horticulturists. The aim of the current study was to determine the antioxidant capacity as hyperoside and anthocyanin content of ten different Iranian pomegranate cultivars. Spectroscopic analyses of the pomegranate showed Black peel cultivar had the highest hyperoside content (25.93 +/- 2.87, 620.41 +/- 30.32 mg/100 g) in its pulp and peel, respectively. Based on this study, the amounts of anthocyanin in pulp ranged between 1.56 +/- 0.05 and 3.89 +/- 0.07 mg g(-1) which related to Sweet white peel and Sweet alac cultivars, respectively. More over the highest and also the lowest peel anthocyanin contents related to these cultivars. The results revealed that the hyperoside and also anthocyanin peel content of each variety is higher than its pulp content. In addition the potency of black peel (Medicinal pomegranate) and Sweet alac cultivars for prevention of coronary heart disease and hypertension were presented.

Antioxidant properties of peel and pulp hydro extract in ten Persian pomegranate cultivars.

This study compares the antioxidant activity of ten different pomegranate cultivars grown in Iran using the ferric reducing power assay (FRAP assay), which is based on the reduction of a ferric-tripyridyl triazine complex to its ferrous, colored form in the presence of antioxidants. Aqueous solutions of known Fe(+2) concentration, in the range of 100-1000 micromol L(-1) were used for calibration. The results showed that among pulp and peel fractions the sour alac and sweet white peel cultivars had more FRAP value respectively. The pomegranate peel extract had markedly higher antioxidant capacity than the pulp extract. The peel extract of sweet white peel cultivar appeared to have more potential as a health supplement rich in natural antioxidants compared to the pulp and peel extracts of other pomegranate cultivars.

Gas-chromatographic fatty-acid fingerprints and partial least squares modeling as a basis for the simultaneous determination of edible oil mixtures.

Partial least squares modeling and gas-chromatographic fatty-acid fingerprints are reported as a method for the simultaneous determination of cottonseed, olive, soybean and sunflower edible oil mixtures. In this work, two sets of three- and four-component combinations of oils were prepared, hydrolyzed and the obtained free fatty acids analyzed by gas chromatography (GC) without any further derivatization. The normalized percentages of the myristic (14:0), palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2) and linolenic (18:3) acids were chromatographically measured in samples and used for constructing calibration matrix. The cross-validation method was used to select the number of factors and the proposed methods were validated by using two sets of synthetic oil mixture samples. The relative standard error for each oil in mixture samples was less than 10%. This approach allows determining possible adulteration in each of the four edible oils.