In vitro antifungal activity of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol against mycotoxigenic plant pathogens

The aim of this study was to examine the effect of five naturally occurring compounds from essential oils on 10 different species of mycotoxigenic fungi involved in several plant diseases. The antifungal activities of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol were observed in?vitro on Fusarium subglutinans, Fusarium cerealis, Fusarium verticillioides, Fusarium proliferatum, Fusarium oxysporum, Fusarium sporotrichioides, Aspergillus tubingensis, Aspergillus carbonarius, Alternaria alternata and Penicillium sp. The naturally occurring compounds tested showed toxic effects on in?vitro mycelium growth of all fungal species but with different level of potency. The results are encouraging for further investigations of in planta antifungal activities of these essential oils components.     

In vitro α-glucosidase and pancreatic lipase inhibitory activities and antioxidants of Samnamul (Aruncus dioicus) during rehydration and cooking

In vitro α-glucosidase and pancreatic lipase inhibitory activities of ethanol extracts of samnamul (dried young shoots of Aruncus dioicus) during rehydration (soaking, 30 min boiling, and re-soaking in water) and subsequent cooking at 180°C with/without perilla oil were determined for evaluation of its anti-diabetic and antiobesity potential. Polyphenol and flavonoid contents were monitored by spectrophotometry. Rehydration and boiling of samnamul reduced α-glucosidase and pancreatic lipase inhibitory activities as well as polyphenol and flavonoid contents, whereas soaking time did not have a significant effect. Of the rehydration and cooking processes, 30 min boiling was the most critical in reducing anti-diabetic and anti-obesity activities as well as antioxidant contents. Perilla oil addition improved α-glucosidase inhibitory activity, possibly through polyphenol addition. These results suggest that dietary intake of samnamul can reduce the risks of diabetes and obesity, and perilla oil can additionally improve its health benefits.     

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B(1) production at different interacting environmental conditions, in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B(1) binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B(1) production were carried out in?vitro under different regimes of a (w) (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB(1) in?vitro. A significant decrease of AFB(1) levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400?ng?ml(-1). S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB(1) production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.     

Steam explosion improves extractability,antioxidant activity and α-glucosidase inhibitory activity of the constituents of Java tea (Clerodendranthus spicatus)

In this work, the steam explosion (SE) technology was exploited to extract valuable phytochemicals from Java tea (Clerodendranthus spicatus). Modification effects of SE on apparent morphology and physicochemical properties of Java tea were investigated to confirm that SE destroyed the cell wall structure and enhanced pore space, which facilitated the dissolution of ingredients. After SE pretreatment, the contents of phenolics, triterpenes, and sterols of Java tea extracts were maximally increased by 40.68%, 25.69%, and 40.11% in the leaves group, and increased by 147.09%, 204.50%, and 115.24% in the stems group, respectively. The antioxidant and α-glucosidase inhibition capacity of extracts were also obviously enhanced. Multivariate analysis indicated that phenolics and triterpenes were the main active substances in the extracts, and the leaves treated at 1.0 MPa and stems treated at 2.4 MPa showed higher comprehensive score. This study provided a promising method for Java tea pretreatment for improving extractability and bioactivity.     

Antimicrobial activity of Yerba Mate (Ilex paraguariensis) aqueous extracts against Escherichia coli O157:H7 and Staphylococcus aureus

Abstract: Bioactive compounds from natural plant sources are becoming increasingly important to the food industry. Ilex paraguariensis is used in the preparation of a widely popular tea beverage (Yerba Mate) in the countries of Uruguay, Paraguay, Argentina, and Brazil. In this study, extracts of 4 brands of commercial tea, derived from the holly plant species, Ilex paraguariensis, were evaluated for their ability to inhibit or inactivate bacterial foodborne pathogens. The ultimate goal was to evaluate potential use of the extracts in commercial applications. Dialyzed aqueous extracts were screened for antimicrobial activity against Escherichia coli O157:H7 and Staphylococcus aureus. S. aureus was found to be the more sensitive to extracts than E. coli O157:H7. Minimum bactericidal concentrations (MBCs) were determined to be approximately 150 to 800 μg/mL and 25 to 50 μg/mL against E. coli O157:H7 and S. aureus, respectively. A Uruguayan brand had reduced activity against E. coli O157:H7 compared to the Argentinean brands tested. It was concluded that Yerba Mate could be used as a potential antimicrobial in foods and beverages against these pathogenic bacteria. Practical Application: Soluble extracts from Yerba Mate are natural antimicrobials that can be incorporated into food products to achieve longer shelf life.     

Effect of storage temperature on survival and growth of foodborne pathogens on whole, damaged, and internally inoculated jalapeños (Capsicum annuum var. annuum)

There is a lack of general knowledge regarding the behavior of foodborne pathogenic bacteria associated with jalape?o peppers. The survival and growth behaviors of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica on the interior and exterior of jalape?o peppers were determined under different storage conditions. Jalape?os were inoculated with a five-strain cocktail of L. monocytogenes, E. coli O157:H7, or S. enterica on the intact external surface, injured external surface, or intact internal cavity of jalape?o peppers and held at 7 or 12°C for a period of 14 days. Populations of each pathogen were determined at 0, 1, 2, 5, 7 10, and 14 days throughout storage. The uninjured, intact external surface of jalape?o peppers did not support growth of the pathogens tested under both storage conditions, with the exception of L. monocytogenes at 12°C. Populations of E. coli and S. enterica declined on the external injured surface of peppers at 7°C, but populations of L. monocytogenes remained consistent throughout the length of storage. At 12°C, L. monocytogenes and S. enterica populations increased throughout storage, and E. coli populations remained unchanged on injured surfaces. The uninjured internal cavity of the jalape?o supported growth of all pathogens at 12°C. Overall, L. monocytogenes was the microorganism most capable of growth and survival in association with jalape?o peppers for the scenarios tested. Results emphasize the importance of jalape?o pepper quality and proper storage conditions in preventing or reducing pathogen survival and growth.     

A lectin from the rhizomes of turmeric (Curcuma longa L.) and its antifungal, antibacterial, and α-glucosidase inhibitory activities

A Curcuma longa L. lectin was purified by aqueous extraction, 80% ammonium sulfate precipitation and ConA Sepharose affinity chromatography. Its specific activity was of 64,566 HU/mg protein for a yield of 41.2% total protein. The molecular weight is of 17.3 kDa. It has hemagglutinating activity against human blood group B, rabbit, mouse, rat, guinea pig, geese, and sheep erythrocytes. The optimum pH is between 6–7, and stable up to 40°C. Activity was stimulated by Ca²⁺ and Mn²⁺. The internal sequence indicated similarity with legume lectin family. Moreover, at concentration of 47 and 94 mg/0.3 cm² disc showed antifungal activity against Exserohilum turicicum, Fusarium oxysporum, and Colectrotrichum cassiicola. The minimal inhibitory concentration were 0.002, 0.005, 0.011, 0.09, and 0.046 mg/mL Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Escheriehia coli, and Candida albicans, respectively. Additionally, it contains a high α-glucosidase inhibitory activity with an IC₅₀ of 8 mg/mL.     

Antioxidant and hepatoprotective activity of kaempferol 3-O-β-d- (2,6-di-O-α-l-rhamnopyranosyl)galactopyronoside against carbon tetrachloride-induced liver injury in mice

Food Science and Biotechnology - This study aims to investigate the antioxidant and hepatoprotective effects of kaempferol 3-O-β-d- (2,6-di-O-α-l-rhamnopyranosyl)galactopyronoside (KG)...     

Changes in antinutrients,phenolics, antioxidant activities and in vitro α-glucosidase inhibitory activity in pumpkin leaves (Cucurbita moschata) during different domestic cooking methods

Food Science and Biotechnology - Pumpkin leaves (Cucurbita moschata) were subjected to different household cooking methods (boiling, microwaving, steaming, and stir-frying) to evaluate their effect...     

Purification, chemical characterization, and antioxidant activity of a polysaccharide from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát)

A purified water-soluble polysaccharide was isolated from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát) using hot water extraction, DEAE Sepharose Fast Flow anion exchange and High-Resolution Sephacryl S-1000 gel-filtration chromatography. The purified polysaccharide was a complex β-d-glucan, with a molecular mass of 230 kDa. Fourier-transform infrared (FT-IR), methylation analysis, and NMR spectroscopy of sanghuang mushroom polysaccharide (PBF3) indicated that the polysaccharide contained (1→3)-β-d-, (1→4)-β-d-, and branched (1→3,6)-β-d-glucopyranosyl residues. On the basis of hydroxyl radical assay, superoxide radical assay, and DPPH radical assay, its antioxidant activities were investigated. PBF3 had significant effect on scavenging hydroxyl radicals, an equivalent inhibiting ability to vitamin C on superoxide radical, and a little lower scavenging activity on DPPH radical than vitamin C, and should be explored as a novel potential antioxidant.     

Protective activity of probiotic bacteria against 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenyl-1H-imidazo[4,5-b]pyridine (PhIP) – an in vitro study

Heterocyclic aromatic amines (HAAs) are carcinogenic compounds present in a typical Western diet rich in thermally processed meat. These nutritional factors can modulate the cytotoxicity of faecal water (FW) and induce tumours in the human gastrointestinal tract. Supplementation with probiotics is promising in terms of reducing the harmful effects of HAAs in the human body. The aim of the study was in vitro assessment of the protective activity of the probiotic strains Lb. rhamnosus 0900, Lb. rhamnosus 0908, Lb. casei 0919 and Lb. casei DN 114001 against IQ (2-amino-3-methyl-3H-imidazo[4,5-f]quinoline) and PhIP (2-amino-1-methyl-6-phenyl-1H-imidazo[4,5-b]pyridine) after incubation with faeces from 15 persons aged 4 months to 82 years (children, adults and the elderly). The highest mean cytotoxicity of FW was observed for the elderly (63.2% ± 3.7%) and the lowest for children (28.0% ± 9.5%), as estimated by a neutral red uptake assay. The probiotics lowered the average cytotoxicity of FW exposed to IQ or PhIP. The concentration of IQ and PhIP in FW was most effectively reduced by Lb. rhamnosus 0900 (47.5%) and Lb. casei 0919 (45.8%), respectively, as determined by high -performance liquid chromatography. All the tested strains bound PhIP to a higher extent than IQ. In an alkaline comet assay, Lb. casei 0919 and Lb. rhamnosus 0908 displayed the strongest protective effect against IQ and PhIP (up to 80% reduction of DNA damage). Also in a comet assay, Lb. rhamnosus 0908 exhibited antioxidative activity toward H₂O₂ and PhIP (up to 63% and 69.5% reduction of oxidative DNA damage, respectively). The protective activity of the probiotic strains was specific to a given person’s FW, which implies the involvement of intestinal microbiota in the process.     

Survival of human norovirus surrogates in milk, orange, and pomegranate juice, and juice blends at refrigeration (4 °C)

Fresh fruits, juices, and beverages have been implicated in human noroviral and hepatitis A virus outbreaks. The purpose of this study was to determine the survival of human norovirus surrogates (murine norovirus, MNV-1; feline calicivirus, FCV-F9; and bacteriophage MS2) in juices (orange and pomegranate juices), juice blends (pomegranate and orange juice) and milk over 0, 1, 2, 7, 14, and 21 days at refrigeration (4 °C). Juices, juice blends, and milk were inoculated with each virus over 21 days, serially diluted in cell culture media, and plaque assayed. MNV-1 showed no reduction in titer after 21 days in orange juice and milk, but moderate reduction (1.4 log) in pomegranate juice from a titer of 5 log(10) PFU/ml. However, MNV-1 was completely reduced after 7 days in the orange and pomegranate juice blend. FCV-F9 from a titer of 6 log(10) PFU/ml was completely reduced after 14 days in orange as well as pomegranate juice and by ～ 3 logs after 21 days in milk at 4 °C. Interestingly, FCV-F9 was completely reduced after 1 day in the orange and pomegranate juice blend at 4 °C. MS2 was reduced by ～ 1.28 log after 21 days in orange juice from a titer of 6 log(10) PFU/ml, and <1 log after 21 days in milk or pomegranate juice, with juice blends showing minimal reduction (<1 log) after 21 days at 4 °C. These results show the survival pattern of noroviruses that aid in the transmission of foodborne viral outbreaks. The data obtained can be used in quantitative viral risk assessment studies and to develop improved measures to prevent virus survival towards controlling outbreaks.     

Phytochemical composition,health effects,and crop management of liquorice (Glycyrrhiza glabra L.): Α medicinal plant

Liquorice has been widely appreciated as an important medicinal plant. Its rhizomes and roots have been used for centuries in traditional medicine due to their renowned therapeutic properties. However, increasing market demands and irrational harvesting of wild liquorice plants has rendered the cultivation of the species of major importance. This review presents aspects related to chemical composition and health effects of the species, and the effect of various cultivation practices. Particular interest is given on glycyrrhizin and its extraction procedures, since it is the main bioactive compound of liquorice roots and its content determines the final product quality.     

TLC–Bioautography-Guided Isolation, HPTLC and GC–MS-Assisted Analysis of Bioactives of Piper betle Leaf Extract Obtained from Various Extraction Techniques: In vitro Evaluation of Phenolic Content, Antioxidant and Antimicrobial Activities

The polyphenolic content, antioxidant and antibacterial activities of the ethanolic extracts of Piper betle leaf obtained from soxhlet (PBSx), sonication (PBSn) and maceration (PBMn) extraction methods were studied. GC–MS analysis was carried out to determine the variation in the phytoconstituents in these extracts. Whereas, thin-layer chromatography (TLC)–bioautography was conducted to localise, separate, and identify antioxidants, and their amount was determined by the newly developed high-performance thin-layer chromatography (HPTLC) method. The results of polyphenolic content, antioxidant assays and antimicrobial assay showed that PBSn contained significant amount of polyphenolics, antioxidant and antimicrobial activity followed by PBMn and PBSx. Moreover, the obtained antioxidant activity of PBSn was significant even in comparison with butylated hydroxytoluene (BHT) and commercially available grape seed extract (GRSx). In addition, GC–MS analysis shown marked variations in the amount of the phytoconstituents among all these extracts with PBSn containing higher amount followed by PBMn and PBSx. TLC bioautography resulted in the separation of three compounds which are identified as eugenol, allylpyrocatechol, and eugenyl acetate. The HPTLC densitometric determination was also supported the results of antioxidant assays by revealing the presence of higher amount of identified antioxidants in PBSn followed by PBMn and PBSx. Since, P. betle leaf extract has been used as one of the ingredients in several herbal formulations, results of this study will not only help the herbal industries in choosing the appropriate extraction technique but also the developed HPTLC method was simple, precise, sensitive and accurate hence can be utilised for the routine quality control and standardisation of formulations containing P. betle leaf extract.     

Electrical stimulation of red deer (Cervus elaphus) carcasses - effects on rate of pH-decline, meat tenderness, colour stability and water-holding capacity

A total of 14 female red deer were included in a study on the effects of low voltage carcass electrical stimulation on meat tenderness, colour stability and water-holding capacity. Carcasses were randomly allocated to either electrical stimulation treatment (ES; 90-95 V unipolar pulses, 7.5 ms duration, 15 Hz for a duration of 55 s) or no electrical stimulation (non-ES) (n=7 in each group). Temperature and pH decline was recorded in M.m. triceps brachii, longissimus dorsi et lumborum (at the last rib; LD) and biceps femoris, at intervals from 0.5 to 20 h post-mortem. At 24 h post-mortem, LD from the left side were excised, vacuum packaged and refrigerated at -1.5°C. Glycogen concentrations, measured at 30 min post-mortem, and ultimate pH did not differ between groups. Compared to controls, ES increased the rate of muscle pH decline and produced lower shear forces at 1 day, 1 week and 3 weeks post-mortem, but these differences disappeared by 6 and 12 weeks post-mortem. Sarcomere lengths at 24 h post-mortem were unchanged by ES. After 1 week of refrigerated storage, ES significantly reduced display life (hours of Minolta a* value ? 12), but this difference disappeared at 3, 6 and 12 weeks of ageing. ES did not affect drip at any ageing time point. The present results demonstrate that the benefits of ES on tenderness are not permanent, and the procedure is not necessary for a long-term, chilled product. This study showed no detrimental effects of using electrical stimulation on meat colour stability or drip loss.     

Structural and physicochemical properties and in vitro digestibility of recrystallized linear α-d-(1 → 4) glucans derived from mild-acid-modified cassava starch

Molecular structure and recrystallization method influence the techno-functional behaviour of recrystallized starch as a functional ingredient in foods. The physicochemical properties of debranched and recrystallized mild-acid-modified cassava starch were studied. Cassava starch was treated with 0.14 mol/L hydrochloric acid for 24, 96 and 216 h at 40 °C prior to debranching with pullulanase. The debranched starches (DS) were recrystallized by annealing (ANN-DS), temperature-cycling (TC-DS) or heat-moisture treatment (HMT-DS) and the particle distribution, crystallinity, thermal properties, solubility, water binding and in vitro digestibility were analyzed. Acid treatment increased the fraction of linear α-d-(1 → 4) glucans comprising 13–30 monomers. Particles comprised loosely to firmly coalesced primary elements forming aggregates of mono- or bi-modal size distribution at ?5 μm and ?20 μm. The relative crystallinities ranged between 31.1–56.1%. Water binding decreased significantly with acid treatment whereas both solubility and water binding were influenced by the recrystallization method and decreased in the order: DS > ANN-DS > TC-DS > HMT-DS. Major thermal transitions occurred at 80–130 °C and 130–160 °C, and the in vitro digestibility rates of 6.8–62.8% correlated significantly (p < 0.001) with relative crystallinity and melting enthalpy.     

Physicochemical,microbiological, and sensory attributes of chitosan-coated grass carp (Ctenopharyngodon idellus) fillets stored at 4°C

This study investigated the effect of chitosan coating (1 and 2%) on the quality of grass carp fillets stored at 4°C for 20 days. During storage, the physicochemical properties (pH, thiobarbituric acid value, total volatile basic nitrogen value, trimethylamine nitrogen value, K-value, water loss, and instrumental texture), microbiology (total viable count and psychrotrophic count), and sensory properties were evaluated. The results showed that chitosan coating could effectively inhibit bacterial growth, improve physicochemical and sensory qualities, and it reduced the deterioration of the quality of grass carp fillets. Compared with fillets without chitosan coating, the shelf life of fillets with 1 and 2% chitosan coating was extended by ~3 and 6–7 days, respectively.