Soluble and insoluble-bound phenolics and antioxidant activity of various industrial plant wastes

The potential of selected industrial food wastes from juice and nut production including apple peel, apple pomace, pomegranate peel, pomegranate seed, chestnut shell, and black carrot pomace as resources for natural antioxidants was investigated. Soluble free and insoluble-bound phenolics were extracted from the wastes and analyzed for total phenolic and flavonoid contents, phenolic profile and antioxidant activity. Total phenolic and total flavonoid contents of wastes were positively correlated with their antioxidant activity. The highest total phenolic and antioxidant activity were determined in soluble fraction of pomegranate peel due to a significant amount of punicalagin derivatives. Pomegranate peel and seed had the most phenolics and flavonoids in soluble form while other wastes had more than 45% of total phenolics in insoluble-bound form. Chestnut shell showed more antioxidant activity in insoluble-bound fraction compared to that of its soluble fraction. These findings showed that not only soluble but also an insoluble-bound fraction of the industrial wastes has good potential for valorization as a source of natural antioxidants

Comparison of enzyme linked immunoassay and high performance liquid chromatography for determination of fumonisin in dried figs

The occurrence of fumonisin in dried figs was investigated by Enzyme Linked Immunoassay (ELISA) and High Performance Liquid Chromatography (HPLC). Total fumonisins (FB1, FB2, FB3) in dried figs were determined using ELISA, whereas only fumonisin B1 (FB1) was determined by HPLC. In the period 2003-2004, one hundred and fifty five dried fig samples were taken during their drying in 7 different districts in the Aegean Region. Among a total of 115 samples, the incidence of total fumonisin in the dried figs was 82% within the range of 0.16 - 108.34 mg/g when determined by ELISA. In comparison, FB1 was detected in 86 samples (74.8%) within the range between 0.046 and 3.649 mg/g by HPLC. Correlation between ELISA and HPLC methods was observed for all samples. However, no correlation between methods was recorded for the samples with less than 1 mg/g Fumonisin B1 level (obtained by HPLC). Although there was a correlation between methods for all the samples, fumonisin levels obtained by ELISA were much higher than those obtained by HPLC. False positive results were obtained by ELISA in 11 out of 115 dried fig samples. The results indicated that ELISA can be used as a screening method for determining the occurence of fumonisin in dried figs

Cardamom, Cumin, and Dill Weed Essential Oils: Chemical Compositions, Antimicrobial Activities, and Mechanisms of Action against Campylobacter spp.

Natural antimicrobials as well as essential oils (EOs) have gained interest to inhibit pathogenic microorganisms and to control food borne diseases. Campylobacter spp. are one of the most common causative agents of gastroenteritis. In this study, cardamom, cumin, and dill weed EOs were evaluated for their antibacterial activities against Campylobacter jejuni and Campylobacter coli by using agar-well diffusion and broth microdilution methods, along with the mechanisms of antimicrobial action. Chemical compositions of EOs were also tested by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results showed that cardamom and dill weed EOs possess greater antimicrobial activity than cumin with larger inhibition zones and lower minimum inhibitory concentrations. The permeability of cell membrane and cell membrane integrity were evaluated by determining relative electric conductivity and release of cell constituents into supernatant at 260 nm, respectively. Moreover, effect of EOs on the cell membrane of Campylobacter spp. was also investigated by measuring extracellular ATP concentration. Increase of relative electric conductivity, extracellular ATP concentration, and cell constituents’ release after treatment with EOs demonstrated that tested EOs affected the membrane integrity of Campylobacter spp. The results supported high efficiency of cardamom, cumin, and dill weed EOs to inhibit Campylobacter spp. by impairing the bacterial cell membrane

A study on correlations between antimicrobial effects and diffusion coefficient, zeta potential and droplet size of essential oils

It was hypothesized that inhibition zone of an essential oil (EO) in a Petri dish might be relevant to its diffusion coefficient (DC) into agar medium, which may be calculated from the Fick's diffusion. Antibacterial activities of cumin, dill weed, fennel, ginger and oregano EOs were evaluated against Campylobacter jejuni and Campylobacter coli. DCs, zeta potential and droplet sizes of EOs were measured. The inhibition zones of EOs had in accordance with DCs whereas they had a reverse relation with droplet size. The measured DCs were in the range of 0.82-1.50 x 10(-12) m(2) s(-1). The effective DC of EOs calculated from the total flux exhibited good correlations with measured DCs. Outcomes of this study may provide a pre-assessment for the antimicrobial activity of any EOs from its DC. Furthermore, it may help to understand the studies on how EOs pass through a bacterium cell and show antimicrobial effects.Hebei Provincial and University Science & Technology Cooperation and Development fund support project [130127]; Key Project of Philosophy and Social Sciences Research, Ministry of Education (China) Research on Green Design in Sustainable Development [16JZDH014, 16JZD014]Hebei Provincial and University Science & Technology Cooperation and Development fund support project (No. 130127) and the Key Project of Philosophy and Social Sciences Research, Ministry of Education (China) Research on Green Design in Sustainable Development(contract No. 16JZDH014, approval No. 16JZD014).WOS:0005930150000072-s2.0-8509085675

Angiotensin-I-Converting Enzyme (ACE)-Inhibitory Peptides from Plants

Hypertension is an important factor in cardiovascular diseases. Angiotensin-I-converting enzyme (ACE) inhibitors like synthetic drugs are widely used to control hypertension. ACE-inhibitory peptides from food origins could be a good alternative to synthetic drugs. A number of plant-based peptides have been investigated for their potential ACE inhibitor activities by using in vitro and in vivo assays. These plant-based peptides can be obtained by solvent extraction, enzymatic hydrolysis with or without novel food processing methods, and fermentation. ACE-inhibitory activities of peptides can be affected by their structural characteristics such as chain length, composition and sequence. ACE-inhibitory peptides should have gastrointestinal stability and reach the cardiovascular system to show their bioactivity. This paper reviews the current literature on plant-derived ACE-inhibitory peptides including their sources, production and structure, as well as their activity by in vitro and in vivo studies and their bioavailability

Antibacterial, Antifungal, Antimycotoxigenic, and Antioxidant Activities of Essential Oils: An Updated Review

The interest in using natural antimicrobials instead of chemical preservatives in food products has been increasing in recent years. In regard to this, essential oils-natural and liquid secondary plant metabolites-are gaining importance for their use in the protection of foods, since they are accepted as safe and healthy. Although research studies indicate that the antibacterial and antioxidant activities of essential oils (EOs) are more common compared to other biological activities, specific concerns have led scientists to investigate the areas that are still in need of research. To the best of our knowledge, there is no review paper in which antifungal and especially antimycotoxigenic effects are compiled. Further, the low stability of essential oils under environmental conditions such as temperature and light has forced scientists to develop and use recent approaches such as encapsulation, coating, use in edible films, etc. This review provides an overview of the current literature on essential oils mainly on antifungal and antimycotoxigenic but also their antibacterial and antioxidant activities. Additionally, the recent applications of EOs including encapsulation, edible coatings, and active packaging are outlined.WOS:0005855377000012-s2.0-85093665751PubMed: 3306661

Investigating the antioxidant and antimicrobial activities of different vinegars

Capanoglu, Esra/0000-0003-0335-9433; Guler, Funda Karbancioglu/0000-0001-6576-0084; Devecioglu, Dilara/0000-0001-6681-0944WOS: 000414155800002In this study, the antioxidant contents and the antimicrobial activities of 18 vinegar samples were investigated. For this purpose, total flavonoid contents (TFC) and total phenolic contents (TPC) of different vinegar samples were determined. in addition, total antioxidant capacities (TAC) of vinegars were analyzed using four different in vitro tests: ABTS, CUPRAC, DPPH, and FRAP, in parallel. Results obtained from antioxidant analyses showed that balsamic vinegar had the highest TFC (96 +/- 18 mg CE/100 mL) and TPC values (255 +/- 24 mg GAE/100 mL), as well as the highest TAC determined using CUPRAC (709 +/- 108 mg Trolox/100 mL) and FRAP (421 +/- 28 mg Trolox/100 mL) methods. the phenolic profiles of vinegar samples were identified by performing HPLC analysis. Among all vinegar samples studied, the most abundant phenolic compounds were determined to be gallic acid, protocatechuic acid, and p-hydroxybenzoic acid. Furthermore, antimicrobial activities of different vinegars, against Staphylococcus aureus, Salmonella Typhimurium, and Escherichia coli, were evaluated using disc diffusion method; the results of which were related to the acetic acid contents and the pH values of the vinegar samples. Balsamic vinegar was again determined to be the sample that had the highest antimicrobial activity, which showed a strong antibacterial activity against S. Typhimurium. Antibacterial activities of vinegars could partly be related to both their acetic acid contents and the pH values, and also to their phenolic contents.Istanbul Technical University, Scientific Research Projects (BAP) UnitIstanbul Technical UniversityThis study was financially supported by the Istanbul Technical University, Scientific Research Projects (BAP) Unit. We also thank Mehmet Basri Celiker and Kuhne Co. (Kemalpasa, Izmir, Turkey) and also Erkan Tekgunduz and Icmeli Dogal Urunler Co. for supplying the samples