68 research outputs found

    Phenolic content of apple juice for cider making as influenced by common pre-fermentation processes using two analytical methods

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    Pre-fermentation methods can influence the cider produced from apple juice. This study analyses the influence of pre-fermentation methods; maceration and press fractioning, on the total phenolic content of juice from four apple varieties; ‘Red Delicious’, ‘Pink Lady’, ‘Sturmer’, and ‘Bulmer’s Norman’. The must was macerated for 0 or 2 h and juice was collected at free run or under 200 kpa. Base juice characteristics and total phenolic content was analysed using the Folin-Ciocalteu method and spectrophotometric absorbance at 280 nm (A280), a method used for the analysis of white wine. Both methods of analysing the total phenolic content were used, measuring the same samples to determine if the methods are comparable. No interaction was found between pre-fermentation technique and the results varied by variety and analytical method. High pressure improved the phenolic extraction for ‘Bulmer’s Norman’ juice compared to free run juice when analysed by A280. Non-macerated juice had higher total phenolic content than macerated juice for ‘Red Delicious’ and ‘Pink Lady’ juice when analysed using the Folin–Ciocalteu method. There was a moderate positive correlation between the analytical methods

    A comparison of laboratory analysis methods for total phenolic content of cider

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    Total phenolic content is widely accepted as a key measure of quality for cider. Apple juice and cider, made from six apple varieties including dessert and cider apples, were analysed for total phenolics using three different methods: (a) the Folin-Ciocalteu method, (b) the Somers method (a spectrophotometric method developed specifically for wine), and (c) ultra-performance liquid chromatography (UPLC) as a benchmark test. Of these approaches, the Somers method had the strongest correlation with UPLC with an R2 value of 0.99, whilst the Folin-Ciocalteu correlated with UPLC with an R2 value of 0.89. The Folin-Ciocalteu method also had a strong positive correlation with the Somers approach with an R2 value of 0.91. Correlations between methods were strongest for apple varieties that were naturally high in phenolic content. These results highlight the potential of the Somers method to rapidly, inexpensively, and accurately report the total phenolic content of apple juice and ciders made from dessert and cider apple varieties

    Eight new species of Gomphichis (Orchidaceae, Spiranthoideae) from Colombia

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    Eight new species of the genus Gomphichis from Colombia are described. Each species is illustrated, and detailed habitat and distribution data are provided. A distribution map of the new species is presented. A dichotomous key for determination of the Gomphichis species in northern South America is provided. Conservation status assessments are provided for each species; current International Union for Conservation of Nature (IUCN) Red List categories and criteria are listed. A brief discussion of spiranthoid orchids taxonomy, conservation status of species, endemism in the Andes and paramo are presented

    Are food-deceptive orchid species really functionally specialized for pollinators?

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    Food-deceptive orchid species have traditionally been considered pollination specialized to bees or butterflies. However, it is unclear to which concept of specialization this assumption is related; if to that of phenotypic specialization or of functional specialization. The main aim of this work was to verify if pollinators of five widespread food-deceptive orchid species (Anacamptis morio (L.) R.M. Bateman, Pridgeon & M.W. Chase, Anacamptis pyramidalis (L.) Rich., Himantoglossum adriaticum H. Baumann, Orchis purpurea Huds. and Orchis simia Lam.) predicted from the phenotypic point of view matched with the observed ones. We addressed the question by defining target orchids phenotypic specialization on the basis of their floral traits, and we compared the expected guilds of pollinators with the observed ones. Target orchid pollinators were collected by conducting a meta-analysis of the available literature and adding unpublished field observations, carried out in temperate dry grasslands in NE Italy. Pollinator species were subsequently grouped into guilds and differences in the guild spectra among orchid species grouped according to their phenotype were tested. In contradiction to expectations derived from the phenotypic point of view, food-deceptive orchid species were found to be highly functionally generalized for pollinators, and no differences in the pollinator guild spectra could be revealed among orchid groups. Our results may lead to reconsider food-deceptive orchid pollination ecology by revaluating the traditional equation orchid-pollination specialization

    Plant community attributes affect dry grassland orchid establishment

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    Several factors have been taken into account to explain the distribution of orchid species. We explored the extent to which plant community attributes affect the abundance and reproductive fitness of three orchid species (Anacamptis morio, Himantoglossum adriaticum and Ophrys sphegodes), native to dry grasslands. Structural attributes of plant community (e.g. cover and height) were assessed in ninety 4 m(2) plots scattered on three hill massifs of the Veneto Region (NE Italy). For the three target orchid species, the height of the flowering stalk, the relative ramet height and the number of flowers and fruits were recorded in 203 tagged ramets. Generalized Linear Model revealed that plant community attributes such as cover and height of the herb layer exert a negative effect on the abundance of orchid populations. Furthermore, regression models indicated that O. sphegodes and H. adriaticum reproductive fitness, determined as fruit/flower ratio, was positively affected by relative ramet height. Our results revealed that local herbaceous vegetation structure influences the cover and fruit set of target orchid species. However, there can be substantial variation in the response of different species and variation in the structural attributes of surrounding vegetation may be associated with differences in the strength of selection. In order to achieve effective results in orchid species conservation, protocols for the in situ conservation must detail the range of vegetation covers and heights at which orchid species are favoured and can produce the most effective inflorescences
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