1,721,069 research outputs found
Carotenoid content and pulp colour non-destructively measured by time-resolved reflectance spectroscopy in different cultivars of Brazilian mangoes
No full textCarotenoid biosynthesis is one of the most important biochemical changes occurring during mango ripening. Carotenoids are responsible for the yellow-orange pulp colour, which is one of the best maturity indices for mangoes, notwithstanding it is a destructive method. Time-resolved reflectance spectroscopy (TRS) is a nondestructive technique which simultaneously quantifies the internal optical properties of fruit related to pigments (absorption coefficient, μa) and to structure (reduced scattering coefficient, μs') by probing the pulp to a depth of 1-2 cm with no or limited influence from the skin. In previous works, it was found that TRS is able to predict with good accuracy the pulp colour of mangoes and then to sort fruit with different maturity degrees. The aim of this research was to study the relationships among TRS optical properties, total carotenoids content and pulp colour parameters of two cultivars of Brazilian mangoes transported by plane to Italy. Fruit were measured by TRS in the 540-690 nm range for 'Palmer' cultivar and in the 540-780 nm range for 'Haden' and analyzed for pulp colour and total carotenoids content. Total carotenoids ranged from 5.2 to 32.7 mg kg-1 FW for 'Palmer' and from 5.9 to 56.2 mg kg-1 FW for 'Haden'. By using partial least squares regression, good correlations were obtained between TRS absorption spectra and total carotenoids content (R2cv=0.83 and 0.93 for 'Haden' and 'Palmer', respectively) and pulp colour parameters (R2cv=0.78-0.96)
Formulazione Adimensionale per la Caratterizzazione delle Prestazioni di un Idrogetto ad Imbocco Obliquo
No full text61° CONGRESSO NAZIONALE ATI, PERUGIA, SETTEMBRE 2006
Eating quality of ‘Abate Fetel’ pears stored in dynamic CA in relation to maturity at harvest
No full text‘Abate Fetel’ is considered a high-quality pear cultivar in Italy due to its excellent eating quality. Maturity at harvest and storage protocol strongly affect quality. This work aimed at studying the eating quality of ‘Abate Fetel’ pears after storage under dynamic controlled atmosphere (DCA) and in air (NA) in relation to fruit maturity non-destructively measured at harvest by time-resolved reflectance spectroscopy (TRS). At harvest 150 pears were measured for μa670 by TRS, classified in less-LeM, mediumMeM and more-MoM maturity classes, and stored for 12 weeks in NA and DCA (0.8 kPa O2, 0.45 kPa CO2) at -0.5°C. At harvest and after 4 and 7 d post-storage shelf life, pears were analysed for firmness, soluble solids (SSC), acidity (TA), sugar and organic acid composition, and 7 d LeM and MoM pears were submitted to sensory analysis. At harvest LeM fruit had higher firmness and glucose and lower sucrose content than MoM ones. PCA analysis on storage data explained 70.4% of variance. PC1 opposed mechanical and sensory firmness, graininess, astringency, SSC and sucrose to juiciness and glucose. PC2 grouped sweetness, sourness, juiciness, aroma, TA, sorbitol and malic acid against mechanical and sensory firmness. NA-MoM pears showed the highest PC1 scores and negative PC2 scores, being the firmest, the grainiest, the least juicy with the highest sucrose and citric acid contents. NA-LeM fruit had negative PC1 and PC2 scores, being the least sweet, acid and aromatic with low amounts of fructose and malic acid. DCA-MoM fruit had the highest PC2 scores with low but positive PC1 scores and were characterized by the highest sweetness and acidity, high TA, fructose and malic acid contents and the highest scores for aroma. DCA pears showed the lowest PC1 scores and high PC2 scores in LeM fruit. DCA-LeM pears were the juiciest, the least grainy and astringent with the highest amount of glucose. Our results indicate that classifying pears at harvest in homogeneous maturity classes by using TRS allow to better define the best storage practices in order to obtain fruit with quality characteristics that can satisfy the consumer expectations
Quality and nutraceutical properties of mango fruit: Influence of cultivar and biological age assessed by time‐resolved reflectance spectroscopy
Full text linkThe content and composition of the main antioxidants in the pulp of mangoes depend also on cultivar and maturity degree, the latter being non-destructively evaluated by the absorption coefficient measured by Time-resolved Reflectance Spectroscopy (TRS) at 540 nm (μa540). Aiming at evaluating the levels of antioxidants [carotenoids (CAR), phenols (TPC), ascorbic acid (AA)] and antioxidant capacity (TAC) in relation to μa540 maturity class, selected ‘Haden’ and ‘Palmer’ mangoes were measured for μa540 by TRS, classified based on μa540 value as less (LeM), medium (MeM) and more (MoM) mature and analyzed for pulp firmness, pulp color (a*, h°, Yellowness Index), CAR (total and composition by HPLC‐DAD), TPC, AA and TAC. ‘Palmer’ fruit had higher TPC, AA and TAC than ‘Haden’ mangoes. On average MoM fruit showed higher TPC, total CAR, total all‐trans‐violaxanthin esters and all‐trans‐β‐carotene than MeM and LeM fruit. LeM fruit did not have compounds belonging to the 9‐cis‐violaxanthin group, while cis‐β‐cryptoxanthin was approx. 19% of total carotenoids. In MoM mangoes the main carotenoid was all‐trans‐β‐carotene (53%), followed by total all‐trans‐violaxanthin esters (30%), 9‐cis‐violaxanthin group (8%) and cis‐β‐cryptoxanthin (6%). The μa 540 significantly correlated (r=0.78‐0.94) with total CAR, all‐trans‐β‐carotene, all‐trans‐violaxanthin no.3 (both cultivars), TPC, all‐trans‐violaxanthin no.1, no.2, no.6 (‘Haden’), and 9‐cis‐violaxanthin no.2, no.3 (‘Palmer’). Our results indicate that TRS is suitable to non‐destructively measure the pulp color of mangoes and to sort fruit with different ripening degree and nutraceutical properties
Non-destructive assessment of pulp colour in mangoes by time-resolved reflectance spectroscopy: Problems and solutions
No full textPulp colour in mangoes turns from greenish to deep orange with maturity, and is one of the most reliable maturity indices used in several production regions, even if it is a destructive measurement. Time-resolved reflectance spectroscopy (TRS) is a nondestructive technique which simultaneously quantifies the internal optical properties of fruit related to pigments (absorption coefficient, μa) and to structure (reduced scattering coefficient, μs') by probing the pulp at a depth of 1-2 cm with no or limited influence from the skin. TRS has been used to study the internal fruit attributes related to maturity; the μa measured at harvest at 630-670 nm has been used to predict softening rate during shelf life in nectarines and mangoes. The results obtained in 2011-2012 seasons with Brazilian mangoes are presented analysing various aspects and problems of the TRS measurement for this type of fruit. The relationships between maturity at harvest measured by μa, TRS optical properties in shelf life, fruit softening and pulp colour were studied in 'Haden', 'Palmer' and 'Tommy Atkins' mangoes. 'Haden' and 'Palmer' fruit (less advanced maturity) could be sorted using μa650-μa690, near the chlorophyll absorption peak. In contrast, 'Tommy Atkins' fruit, which were selected for shipping (more advanced maturity), were successfully sorted according to μa540, near the carotenoids absorption peak. It was confirmed that TRS non-destructively measures pulp colour, as shown by the high correlations between μa540 and a∗, hue and yellowness index (IY) and the good performances of PLS models based on μa540-900 spectra for a∗, hue and IY prediction
Sensory profiles of various stored fruit species are affected by maturity class assessed by time-resolved reflectance spectroscopy at harvest
Full text linkThe absorption coefficient measured at harvest at 670 nm (μa670) by timeresolved reflectance spectroscopy (TRS) is a non-destructive maturity index used to evaluate the biological age of fruit, i.e., the fruit maturity stage. The μa670 was successfully used to classify nectarine, apple and mango fruit into maturity classes each one having distinctive ripening behaviors. Aiming at studying the influence of TRS maturity class assessed at harvest on the sensory profiles of various fruit species after storage, 'Jonagored' apples, 'Abbé Fétel' pears, 'Morsiani 90' nectarines and 'Spring Belle' peaches were measured at harvest by TRS at 670 nm, ranked on the basis of decreasing μa670 (increasing maturity) and classified as less (LeM), medium and more (MoM) mature. Then fruit were randomized into batches of 30 fruits, each one corresponding to a storage atmosphere (apples: CA, NA; pears: CA, NA, DCA) or to a storage temperature (peaches, nectarines: 0, 4°C). After storage, fruit were put in shelf life at 20°C to reach the ripening degree for consumption. Sensory analyses (QDA profiles) were carried out on LeM and MoM fruit using a panel of 10 assessors. Our results indicate that, for all the species, besides the influence of storage conditions, there was also a great influence of TRS maturity classification at harvest. MoM apples and pears developed physiological disorders such as mealiness and graininess when stored in NA, whereas showed well balanced sensory characteristics when stored in CA and DCA, becoming after storage soft, juicy, sweet, but sour enough. MoM nectarines stored both at 0 and 4°C became woolly, while the LeM ones stored at 0°C developed the best sensory characteristics. MoM peaches stored at 0°C showed the best sensory profile and the LeM ones stored at 4°C the worst. So TRS maturity classification at harvest can give indications on the best storage conditions in order to obtain fruit with sensory characteristics than can satisfy the consumer
Modeling mango ripening during shelf life based on pulp color nondestructively measured by time-resolved reflectance spectroscopy
Full text linkNon-destructive techniques could help mango growers to pick fruit at the proper maturity degree and to monitor fruit quality during storage and marketing to satisfy the consumer expectations. The absorption coefficient non-destructively measured at 540 nm (μa540) by time-resolved reflectance spectroscopy (TRS) was shown to be a maturity index for mango fruit and was highly correlated with pulp color parameters and carotenoids content. The aim of this work was to model μa540 using the biological shift factor theory to verify if μa540 is able to assess the maturity degree of individual mango fruit and then to use μa540 to model pulp color in order to relate μa540 to an important index of mango ripening. Mango fruit (Mangifera indica L. cv Tommy Atkins) at commercial maturity for ship and air transport maturities, were measured by TRS, ranked according to decreasing μa540 (decreasing maturity), randomized into six batches per transport maturity and analyzed for μa540 and pulp color parameters after 0, 1, 2, 5, 6 and 7 days of shelf life at 20 °C. The μa540 as a function of biological shift factor increased during ripening following a logistic/exponential model (R2adj=99%) with a faster rate in less mature fruit than in more mature ones. The changes in pulp color during mango ripening depended on fruit maturity (i.e., μa540) and on time of shelf life at 20 °C. By converting the μa540 into the biological shift factor it was possible to model the increasing trend of a*, b*, C*, and IY and the decreasing trend of L* and h° during the shelf life period explaining 91.2–99.8% of the variation and to differentiate mango fruit according to their biological age. Similarly to μa540, color changes occurred earlier in more mature fruit and later in less mature ones with the same pattern in time. There is a synchronization between changes of μa540 and changes of a*, b*, C* and yellowness during ripening in mango fruit which allows to use μa540 to sort fruit according to their maturity degree and then to optimize fruit management along the supply chain
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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