40 research outputs found
Time-resolved reflectance spectroscopy as a management tool for late-maturing nectarine supply chain
The absorption coefficient of the fruit flesh at 670 nm (mu(a)), measured at harvest by time-resolved reflectance spectroscopy (TRS) is a good maturity index for early nectarine cultivars. A kinetic model has been developed linking the mu(a), expressed as the biological shift factor to softening during ripening. This allows shelf life prediction for individual fruit from the value of mu(a) at harvest and the fruit categorization into predicted softening and usability classes. In this work, the predictive capacity of a kinetic model developed using mu(a) data at harvest and firmness data within 1-2 d after harvest for a late maturing nectarine cultivar ('Morsiani 90') was tested for prediction and classification ability. Compared to early maturing cultivars, mu(a) at harvest had low values and low variability, indicating advanced maturity, whereas firmness was similar. Hence, fruit were categorized into six usability classes (from 'transportable-hard' to 'ready-to-eat-very soft') basing on mu(a) limits established analyzing firmness data in shelf life after harvest. The model was tested by comparing the predicted firmness and class of usability to the actual ones measured during ripening and its performance compared to that of models based on data during the whole shelf life at 20 degrees C after harvest and after storage at 0 degrees C and 4 degrees C. The model showed a classification ability very close to that of models based on data of the whole shelf life, and was able to correctly segregate the 'ready-to-eat-transportable', 'transportable' and 'transportable-hard' classes for ripening at harvest and after storage at 0 degrees C, and the 'ready-to-eat-very soft' and 'ready-to-eat-soft' classes for ripening after storage at 4 degrees C, with lower performance of models for fruit after storage at 4 degrees C respect to those of the other two ripening
Do we need imaging to diagnose appendicitis in children?
Background: To evaluate the role of clinical assessment with selective use of imaging studies in the management of suspected acute appendicitis in children. Patients and Methods: Medical records of children referred to Emergency Room in 2010 for suspected appendicitis were retrospectively reviewed. Diagnostic investigations divided by age and sex were related to pathological findings. Negative appendectomy and complication rates were calculated. Results: 923 children needed surgical assessment : i0 n 75.7% of them surgical indication was excluded and 24.3% were admitted to surgical ward for observation. Appendectomy was eventually performed in 137 patients (61.9%), 82.4% of them without any preoperative imaging while 17.6% underwent selective studies, mainly abdominal ultrasonography (14.6%). Imaging was requested twice as frequently in not operated admitted children (39.3%) than in the operated ones (17.5%, P < 0.001). Overall complicated appendicitis rate (peritonitis and abscess) resulted 26.4% and negative appendectomy rate 8.8%. Females older than 10 years presented histologically not-confirmed appendicitis in 22.2% of cases, while the younger ones presented more frequently complicated appendicitis (29.3%). Conclusions: Clinical assessment is the key to diagnose appendicitis. Nevertheless, in girls older than 10 years, selected use of imaging should be implemented to avoid unnecessary appendectomies. Imaging of choice in equivocal cases should be ultrasonography
Studies on classification models to discriminate âBraeburnâ apples affected by internal browning using the optical properties measured by time-resolved reflectance spectroscopy
This work aimed at studying the feasibility of time-resolved reflectance spectroscopy (TRS) to nondestructively detect internal browning (IB) in âBraeburnâ apples through the development of classification models based on absorption (ua) and scattering (us') properties of the pulp.This research was carried out in two seasons: in 2009, apples were measured by TRS at 670 nm and inthe 740â1040 nm spectral range on four equidistant points around the equator, whereas in 2010 appleswere measured by TRS at 670 nm and at 780 nm on eight equidistant points. The values of the absorption coefficients measured in the 670â940 nm range increased with IB devel-opment. On the contrary, us'780 was higher in healthy fruit than in IB ones. The ua780 also significantlyincreased with IB severity, showing high values when IB affected the pulp tissues compared to the coreones. Also ua670 changed with IB development, but it was not able to clearly discriminate healthy fruitfrom IB ones because its value was also affected by the chlorophyll content of the pulp. The absorption and scattering coefficients were used as explanatory variables in the linear discriminant analysis in order to classify each apple tissue as healthy or IB; then the models obtained were used forfruit classification. The best classification performance was obtained in 2010 using ua780 and us'780and considering the IB position within the fruit: 90% of healthy fruit and 71% of IB fruit were correctly classified. By using all the ua measured in the 670â1040 nm range plus the us'780, IB fruit classification was slightly better while healthy fruit classification was worse. The better result of 2010 was due tothe increased number of TRS measurement points that allowed better exploration of the fruit tissues. However, the asymmetric nature of this disorder makes detection difficult, especially when the disorderis localized in the inner part of the fruit (core) or when it occurs in spots. A different TRS set-up (position and distance of fibers, time resolution) should be studied in order to reach the deeper tissue within the fruit in order to improve browning detection
Relationship between texture sensory profiles and optical properties measured by time-resolved reflectance spectroscopy during post-storage shelf life of 'Braeburn' apples
Abstract
âBraeburnâ apples from three harvests after 6-month storage in controlled atmosphere were measured at 670 nm by time-resolved reflectance spectroscopy (TRS), ranked on decreasing ÎŒ
a670 (increasing maturity), classified as less (LeM), medium and more mature (MoM), randomised into three batches per harvest and analysed after 1, 8 and 14 days of shelf life. LeM and MoM apples were measured in the 630-900 nm range by TRS, and analysed for sensory profile (firm, crispy, juicy, mealy) and pulp mechanical characteristics (firmness, stiffness, energy-to-rupture). All data were processed by Principal Component Analysis (PCA). According to sensory intensity scores, fruits were either divided into five classes (very low â VL; low â L; medium â M; high â H; very high â VH) separately for every attribute, or clustered into four groups, each one representing a specific sensory profile. The absorption spectra showed a maximum at 670 nm (chlorophyll-a) and ÎŒ
a670 was higher in the VH class for firm, crispy and juicy and in the VL and L classes for mealy. The scattering spectra had a decreasing trend with the wavelength increase, and Ό
sâ values were lower in the VH class for firm and crispy, and higher in the VH class for mealy and in the VL ones for juicy. PCA underlined that ÎŒ
sâ values were negatively related to firmness and ÎŒ
a670, and that Ό
a690, Ό
a730, Ό
a830, Ό
a850 and Ό
a900 were opposed to mealiness. PC scores differed among the four sensory profiles and increased from VL to VH classes for firmness, crispiness and juiciness and from VH to VL classes for mealiness.</jats:p
Optical properties, ethylene production and softening in mango fruit
Firmness decay, chlorophyll breakdown and carotenoid accumulation, controlled by ethylene, are major ripening events in mango fruit. Pigment content and tissue structure affect the optical properties of the mesocarp, which can be measured nondestructively in the intact fruit by time-resolved reflectance spectroscopy (TRS). This work is aimed at improving the maturity assessment in mango ( Mangifera indica L. cv Haden) from Brazil, using TRS absorption in both the carotenoid and chlorophyll regions in order to develop a model for fruit ripening. Scattering and absorption in the 540-900. nm spectral range by TRS, ethylene production and respiration rate, and firmness, were measured in one day on each individual fruit of a sample covering the range of maturity. The fruit displayed a variability which was attributed to the different biological age. Absorption spectra showed two peaks at 540 and 670. nm, corresponding respectively to the tail of carotenoid absorption and to chlorophyll- a absorption. Carotenoids increased substantially only in fruit where chlorophyll had almost disappeared. The absorptions at 540 and 670. nm, which described the maturity state of each fruit relative to the range of each wavelength, were combined in one index of biological age (biological shift factor) for each fruit and used in logistic models of ethylene increase and firmness decay respectively. The model explained about 80% of the variability in ethylene production rate. A similar result was obtained for firmness when scattering was added in the model. The combination of absorption at 540 and 670. nm measured by TRS in the intact fruit can be used to classify mango fruit according to maturity and to predict the ripening of individual fruit
Quality and nutraceutical properties of mango fruit: influence of cultivar and biological age assessed by Timeâresolved Reflectance Spectroscopy
The 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 (”a540). Aiming at evaluating the levels of antioxidants [carotenoids (CAR), phenols (TPC), ascorbic acid (AA)] and antioxidant capacity (TAC) in relation to ”a540 maturity class, selected âHadenâ and âPalmerâ mangoes were measured for ”a540 by TRS, classified based on ”a540 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. âPalmerâ fruit had higher TPC, AA and TAC than âHadenâ mangoes. On average MoM fruit showed higher TPC, total CAR, total allâtransâviolaxanthin esters and allâtransâÎČâcarotene than MeM and LeM fruit. LeM fruit did not have compounds belonging to the 9âcisâviolaxanthin group, while cisâÎČâcryptoxanthin was approx. 19% of total carotenoids. In MoM mangoes the main carotenoid was allâtransâÎČ-carotene (53%), followed by total allâtransâviolaxanthin esters (30%), 9âcisâviolaxanthin group (8%) and cisâÎČâcryptoxanthin (6%). The ”a540 significantly correlated (r=0.78â0.94) with total CAR, allâtransâÎČâcarotene, allâtransâviolaxanthin no.3 (both cultivars), TPC, allâtransâviolaxanthin no.1, no.2, no.6 (âHadenâ), and 9âcisâviolaxanthin no.2, no.3 (âPalmerâ). 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
Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry
Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase