202 research outputs found

    Combinations of plant-derived compounds against Campylobacter in vitro

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    Campylobacter occur in fresh retail poultry products as a result of their colonization of the gastro-intestinal tract of chickens during growth. Feed additives could be used for suppression of Campylobacter levels in the chickens prior to slaughter. To address this opportunity, feed manufacturers are targeting natural antimicrobials from plant material as new forms of consumer-accepted feed additives. However, to be practical, these natural antimicrobials must be effective at low concentrations. The current study has validated an improved laboratory method to study minimal inhibitory concentrations of plant compounds and their combinations against Campylobacter. The assay was shown to be valid for testing lipid-soluble and water-soluble plant extracts and byproducts from the food industry. The study screened 29 extracts or plant-derived compounds and their mixtures for anti-Campylobacter activity using a laboratory assay. Combinations of oregano, lactic acid, and sorghum byproduct showed effective synergy in anti-Campylobacter activity. The synergies allowed a large reduction in the concentration of the individual compounds needed to kill the bacteria with an 80% reduction in concentration being achieved for oregano essential oil. The assay gives rise to further opportunities for the testing of a greater range of combinations of plant-derived compounds and other natural antimicrobials. The method is robust, simple, and easily automated, and it could be used to adjust the cost of feed formulations by reducing costs associated with antimicrobial feed additives

    Antimicrobial Activity of Nanoencapsulated Essential Oils of Tasmannia lanceolata, Backhousia citriodora and Syzygium anisatum against Weak-Acid Resistant Zygosaccharomyces bailii in Clear Apple Juice

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    The anti-yeast activity of oil-in-water encapsulated nanoemulsion containing individual or a combination of the three essential oils of Tasmanian pepper leaf (Tasmannia lanceolata), lemon myrtle (Backhousia citriodora), and anise myrtle (Syzygium anisatum) against weak-acid resistant Zygosaccharomyces bailii in clear apple juice was investigated. The effectiveness of the shelf-life extension of Z. bailii-spiked (1 × 103 CFU/mL) clear apple juice was evaluated and compared between natural (essential oils) and synthetic (sodium benzoate) antimicrobial agents. Essential oils showed an immediate reduction in the Z. bailii cell population at day-0 and exerted a fungicidal activity at day-4 of storage, with no further noticeable growth at the end of the experiment (day-28). At lower concentrations, Tasmanian pepper leaf oil of 0.0025% had >6 log CFU/mL at day-12 of storage. For lemon myrtle essential oils, the yeast population reached >6 log CFU/mL at day-24 and day-20 for concentrations of 0.02% and 0.01%, respectively. The fungicidal activity of Tasmanian pepper leaf oil reduced from 0.005% to 0.0025% v/v when mixed at a ratio of 1:1 with anise myrtle oil. The results of the present study suggest that these three native Australian herbs have the potential to be used in the beverage industry by controlling Zygosaccharomyces bailii in clear apple juice products. View Full-Tex

    Betalain rich functional extract with reduced salts and nitrate content from red beetroot (Beta vulgaris L.) using membrane separation technology

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    An initial laboratory-scale evaluation of separation characteristics of membranes with nominal molecular weight cut-offs (NMWCO) ranging from 30 kD down to 0.5 kD indicated effective separation of betalains in the 0.5 kD region. Subsequent pilot-level trials using 1 kD, loose reverse osmosis (LRO) and reverse osmosis (RO) spiral-wound membranes showed LRO membrane to be very efficient with up to 96% salt and 47% other dissolved solids removed while retaining majority of the pigment (∼98%) in the betalain rich extract (BRE). The total betalain content in the BRE increased up to 46%, the highest recovery reported so far at pilot scale level. Interestingly, more than 95% of the nitrates were removed from the BRE after the three diafiltrations. These studies indicate that membrane technology is the most efficient technique to produce BRE with highly reduced amounts of salts and nitrate content

    Investigating the Efficacy of Tasmannia lanceolata Extract in Inactivating Fungi and Prolonging the Shelf Life of Date Fruit

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    Date palm (Phoenix dactylifera L.) is one of the world’s oldest cultivated plants. Post-harvest losses of date palm due to fungal contamination reached up to 50% of the total production. This study aimed to investigate the potential of the extract of Tasmanian pepper leaf (TPL) and the non-thermal treatment of photosensitization mediated by curcumin in reducing the fungal contamination and enhancing the shelf life of date palm. In the in vivo storage study, the dates were treated with three different concentrations of TPL extract 12.5, 25, and 50 µg/mL and stored at 30 °C. The findings obtained for the treatment with TPL extract exhibited potent antifungal activity against most of the tested fungi, where minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were < 25 µg/mL for polygodial, the bioactive compound in TPL. The shelf life of date palm treated by 50 µg/mL polygodial was extended up to 21 days, thrice as much as the untreated controls. In contrast, a lower concentration of TPL extract (25 µg/mL polygodial) revealed up to a 15-day shelf life extension compared to untreated dates (7 days). The results obtained from the study suggested that using TPL extracts against pathogenic and spoilage fungi occurring in fresh date fruits is a promising treatment for the shelf life extension of fresh date fruits at room temperatur

    Changes in quality and bioactivity of native food during storage

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    Australian native foods have long been consumed by the Indigenous people of Australia. There is growing interest in the application of these foods in the functional food and complementary health care industries. Recent studies have provided information on the health properties of native foods but systematic study of changes in flavour and health components during processing and storage has not been done. It is well known that processing technologies such as packaging, drying and freezing can significantly alter the levels of health and flavour compounds. However, losses in compounds responsible for quality and bioactivity can be minimised by improving production practices. This report outlines research developed to provide the native food industry with reliable information on the retention of bioactive compounds during processing and storage to enable the development of product standards which in turn will provide the industry with scientific evidence to expand and explore new market opportunities globally

    “Move n’ Learn” A prototype mobile application for museums.

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    Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

    Profiling ellagic acid content: The importance of form and ascorbic acid levels

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    As the importance of plant-based antioxidants to human health becomes clearer there is a rapidly expanding search for rich sources of these compounds. Much attention is currently focussed on the antioxidant potential of ellagic acid (EA). Making assessment difficult is that EA occurs in different forms: free EA, EA glycosides and polymeric ellagitannins. The overall structure of these forms has a pronounced effect on their antioxidant efficiency and is responsible for widely differing reactivity, solubility and hence bioavailability properties. Often associated with EA is vitamin C which also contributes to the plant foods total antioxidant activity. Previous studies have suggested that ascorbic acid may have protective effects on the polyphenol content of plants. With a view to gaining evidence that the bioactive forms of vitamin C influence EA content, several fruits with a range of EA and vitamin C contents were examined. To facilitate a more detailed assessment of the selected fruits antioxidant potential the relative proportions of EA forms were also determined. In strawberries and boysenberries EA content was predominantly in the polymeric form (21% and 12% free EA plus EA glycoside vs total EA levels for strawberry and boysenberry respectively), while in Kakadu plum it was mainly in the free form (70% of total EA). An increasing percentage of dehydroascorbic acid (9 to 14% of total vitamin C) indicating enhanced transformation of ascorbic acid to its oxidative degradation product together with stable free EA levels (≈ 950 mg/100 g DW) over the 4 month frozen storage period for the Kakadu plum samples are consistent with a possible protective effect of EA by ascorbic acid

    The effect of photosensitization mediated by curcumin on storage life of fresh date (Phoenix dactylifera L.) fruit

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    The effect of photosensitization mediated by curcumin (CUR) in sanitizing the fresh date fruit surface was investigated. Approximately 3-4 mu l CUR solution ranging from 1000 to 1800 mu M was sprayed on the date surface, followed by irradiation using blue light at 420 nm for 10 and 15 min at light dosages of 180 J/cm(2) and 270 J/cm(2) respectively. After irradiation, the date was stored at 4 degrees C and 30 degrees C until fungi was visually observed. The combination of CUR and light resulted in significant (p < 0.05) extension of the shelf life and quality of fresh date. The shelf life of date fruit photosensitized by 1400 mu M CUR for 10 min and stored at 30 degrees C lasted for 14 days in comparison to the 7 days for the control, while date stored at 4 degrees C lasted 98 days for the photosensitized fruit compared to the control of 28 days under the same conditions. In addition, no changes in physico-chemical characteristics were observed after treatment. The sanitization treatment of photosensitization mediated by CUR indicated a promising strategy in extending the shelf life of fresh date fruit. Clean and green technologies that are environmentally friendly like photosensitization are preferred by consumers to the synthetic chemicals used in conventional practices for sanitizing food

    Effect of solid-state fermented and enzyme-supplemented lupins on performance and ileal amino acid digestibility in broiler chickens

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    Context: The importance of lupin in animal nutrition has increased over the years due to its moderate protein content and relative availability. Low inclusion rate in broiler diet has been associated with the presence of antinutritional factors. The established beneficial effect of fermentation as a processing strategy and dietary enzyme use in improving the nutritional value of legumes such as lupins, thus, necessitated this study.Aims: This study determined the effect of solid-state fermented lupin (SSFLP) and enzyme-supplemented lupin (LP) on the performance and ileal amino acid digestibility in broiler chickens.Methods: In Experiment 1 (performance trial), a total of 300 day-old Ross 308 male broiler chicks were distributed into six dietary treatments, with five replicates of 10 birds each. Diet 1 was based on a corn–soybean meal (SBM), Diets 2 and 3 contained 250 g/kg LP and 250 g/kg SSFLP respectively. Diet 4 contained 250 g/kg LP + phytase (PHY). Diet 5 contained 250 g/kg LP + xylanase (XYL). Diet 6 contained 250 g/kg LP + PHY + XYL. PHY at 500 phytase units (FTU)/kg and XYL at 1000 units/kg were added to the respective diets. In Experiment 2 (digestibility trial), a total of 240 21-day-old Ross 308 male broiler chicks was assigned to six dietary treatments with five replicate cages of eight birds each. Diet 1 was based on SBM, Diets 2 and 3 contained 650 g/kg LP and 650 g/kg SSFLP respectively. Diet 4 contained 650 g/kg LP + PHY. Diet 5 contained 650 g/kg LP + XYL. Diet 6 contained 650 g/kg LP + PHY + XYL.Key results: Dietary inclusion of SBM and LP + PHY enhanced broiler performance from 1 to 21 days. PHY- supplemented LP diet improved birds’ bodyweight gain and feed intake compared with the rest of the LP diets. Dietary inclusion of LP + PHY + XYL improved the apparent ileal digestibility (AID) of some amino acids (AA). SSF of LP had no effect on the AA contents, lowered AA digestibility and depressed weight gain in the birds. Although SSFLP diet did not improve performance, it effectively increased phosphorus (P) retention in broiler chickens. Feeding SSFLP and enzyme-supplemented LP diets enhanced the AID of calcium and P, as well as calcium retention.Conclusions: Adding supplemental PHY to LP diet enhanced broiler performance, as indicated by the BWG and FI of these birds, which were significantly higher than those of birds fed on other LP-based diets and comparable with those of birds fed on the SBM diet from 1 to 21 days. Although the SSFLP diet did not improve broiler performance, it was effective in increasing P retention when compared with LP diets. The inclusion of LP + PHY + XYL diet improved the AID of amino acids.Implications: SSFLP is a promising feed ingredient and can have a potential application in feed formulation. However, further studies are still needed to be able to clearly understand its effect at a high inclusion level on the performance and ileal amino acid digestibility in broiler chickens. The development of cocktail inoculants to target all ANFs in lupins will definitely open a new window for the poultry feed industry
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