NIR Analysis of Intact Grape Berries: Chemical and Physical Properties Prediction Using Multivariate Analysis

Texture characteristics are valuable parameters in the perceived quality and overall acceptability of fresh fruit. The characterization of grape texture attributes, such as firmness and crunchiness, is usually performed by sensory analysis or instrumental texture analysis. Both methodologies are destructive. Hence, it is not possible to test multiple times or perform any other analysis on the same sample. In this article, near-infrared (NIR) spectroscopy was applied to intact berries of table grape cv. Regal Seedless. NIR spectra were employed to predict both the physical parameter “hardness”, which is correlated with the crunchiness of berry flesh and the sweetness, which is correlated with the total soluble solids content (TSS, as °Brix). The chemometric analysis was carried out exclusively based on an open-source software environment, producing results readily usable for any operator, besides the specific level of experience with NIR spectroscopy

Use of Artificial Neural Networks and NIR Spectroscopy for Non-Destructive Grape Texture Prediction

In this article, a combination of non-destructive NIR spectroscopy and machine learning techniques was applied to predict the texture parameters and the total soluble solids content (TSS) in intact berries. The multivariate models obtained by building artificial neural networks (ANNs) and applying partial least squares (PLS) regressions showed a better prediction ability after the elimination of uninformative spectral ranges. A very good prediction was obtained for TSS and springiness (R2 0.82 and 0.72). Qualitative models were obtained for hardness and chewiness (R2 0.50 and 0.53). No satisfactory calibration model could be established between the NIR spectra and cohesiveness. Textural parameters of grape are strictly related to the berry size. Before any grape textural measurement, a time-consuming berry-sorting step is compulsory. This is the first time a complete textural analysis of intact grape berries has been performed by NIR spectroscopy without any a priori knowledge of the berry density class

Effects of Soil Water Shortage on Seedling Shoot and Root Growth of Saragolle Lucana Tetraploid Wheat (Triticum durum Desf.) Landrace

Ancient wheats may be a source of traits that are useful for the tolerance of climate change foreseen conditions of raising temperatures and low water availability. Previous research has shown a fine root system and a high mass of rhizosheath per unit root mass in the italian durum wheat (Triticum durum Desf) landrace Saragolle Lucana, and this may be relevant for successfully facing adverse conditions during seedling establishment. We investigated the effect of soil water shortage in Saragolle seedlings on root architecture, rhizosheath formation and biomass allocation. Pot experiments were conducted by comparing two levels of soil available water content (AWC): WW (100% of AWC) and DS (50% of AWC). Phenology was delayed by eight days in DS and above and belowground traits were measured at Zadoks 1.3 for each treatment. Biometric data collected at the same phenological stage show that DS plants did not reach the levels of biomass, surface area and space occupation of WW even after attaining the same developmental stage. Namely, plant dimensions were lower at low soil water availability, with the exception of rhizosheath production: DS yielded a 50% increase in rhizosheath mass and 32% increase in rhizosheath mass per unit root mass. The proportion of plant mass reduction in DS was 29.7% for aboveground parts and 34.7% for roots, while reductions in leaf and root surface areas exceeded 43%. The root/shoot mass and area ratios were not significantly different between treatments, and a higher impact on aboveground than on belowground traits at reduced available water was shown only by a lower ratio of shoot height to root depth in DS than in WW. Increases in rhizosheath in absolute and relative terms, which were observed in our experiment in spite of smaller root systems in the ancient durum wheat variety Saragolle lucana at DS, may provide an interesting trait for plant performance in conditions of low soil water availability both for water-related issue and for other effects on plant nutrition and relations with the rhizosphere

A novel low-cost open-hardware platform for monitoring soil water content and multiple soil-air-vegetation parameters

Monitoring soil water content at high spatio-temporal resolution and coupled to other sensor data is crucial for applications oriented towards water sustainability in agriculture, such as precision irrigation or phenotyping root traits for drought tolerance. The cost of instrumentation, however, limits measurement frequency and number of sensors. The objective of this work was to design a low cost "open hardware" platform for multi-sensor measurements including water content at different depths, air and soil temperatures. The system is based on an open-source ARDUINO microcontroller-board, programmed in a simple integrated development environment (IDE). Low cost high-frequency dielectric probes were used in the platform and lab tested on three non-saline soils (ECe1: 2.5 < 0.1 mS/cm). Empirical calibration curves were subjected to cross-validation (leave-one-out method), and normalized root mean square error (NRMSE) were respectively 0.09 for the overall model, 0.09 for the sandy soil, 0.07 for the clay loam and 0.08 for the sandy loam. The overall model (pooled soil data) fitted the data very well (R2 = 0.89) showing a high stability, being able to generate very similar RMSEs during training and validation (RMSE(training) = 2.63; RMSE(validation) = 2.61). Data recorded on the card were automatically sent to a remote server allowing repeated field-data quality checks. This work provides a framework for the replication and upgrading of a customized low cost platform, consistent with the open source approach whereby sharing information on equipment design and software facilitates the adoption and continuous improvement of existing technologies

Uva da tavola ipocalorica, possibilità di coltivazione e nuove prospettive di mercato

According to the CODEX STAN 255 (2007), table grapes can be harvested when the refractometric index reaches at least 16° Brix. Grapes with a lower refractometric index are accepted provided the sugar/acid ratio (Total Soluble Solids/Tritatable Acidity – TSS/TA) is at least equal to 20:1 if the Brix level is comprised between 12.5° and 14° Brix, 18:1 if the Brix level is comprised between 14° and 16° Brix. Some table grapes grown in Mediterranean climate can accumulate TSS higher than 16° Brix, with low levels of acidity, thus leading to a TSS/AT ratio even greater than 30: 1. Grapes that accumulate TSS less than 12.5° Brix and low TA levels, hardly reach the recommended ratio TSS/TA of 20:1, rather stopping at lower values. Based on these considerations in 2012 an experimental trial of four years started on a total of 103 table grape cvs. Phenological phases in relation to the acidic and sugar content were measured in order to assess the TSS/TA ratio and build regression lines with TSS. Almost all cvs. showed a significant linear regression, with R2 values higher than 0.80 and a standard error between 00.18 and 1.74. TSS values of 103 cvs. at TSS/TA ratio of 20:1, predicted by means of linear regression equations, , were subjected to cluster analysis based on Euclidean Distance. We identified nine clusters, of which the first two with the predicted TSS between 10.04° and 11.77° Brix (7 cvs.) and 12.08° and 12.62° Brix (7 cvs.), respectively. Some of the cvs. showing TSS values below 12.5° Brix at the TSS/TA of 20: 1, were subjected to a test panel of 24 tasters, who were asked to indicate the acceptability of these grapes on hedonic scale of 9 points. Preliminary results showed that for some table grapes with TSS below 12.5° Brix, a SST/AT ratio lower than the recommended 20:1 can be proposed, while preserving an acceptability by the consumer. These results suggest a more modern perspective on grapes nutritional intake, which takes into account the real needs of Western countries where diabetes, hyperglycemia, obesity and cardiovascular diseases are the main dismetabolisms arising from a diet too rich in calories. These grapes thus represent a new frontier and an opportunity for producers of table grapes, who want to enterprise a market share on “grape diet”, and represent a genetic basis for breeding aimed at obtaining new hypocaloric grape cultivars

Utilizzo di vitigni di antica coltivazione del Meridione d'Italia per la produzione di vini passiti di pregio

In recent years the wine sector has been characterized by an increased focus on the diversification of wine products. This change has been welcomed by consumers. In fact, today's consumers are willing to experiment with new products and unusual combinationswhich has stimulated research aimed at the discovery of native grape varieties suitable for for winemaking. In this context, particular attention are receiving vines for the production of dessert wines. Many regions have made efforts in the search for varieties and techniques able to better promote the drying process. At CREA-VE Turi-BA, there is an ongoing recovery and exploitation of indigenous grape varieties in the regions of Southern Italy and today more than 3,000 accessions of wine grapes are preserved. In the present work we have investigate the possibility of the use of certain accessions of Vitis vinifera varieties (collection CREA-VE Turi-BA) deemed attractive for the production of dessert wines. Accessions presenting a good sugar content and a good titratable acidity were selected; namely, Greco bianco b. (named Q19) and Mantonico bianco b. (named R8) were compared to the cv of Malvasia di Lipari b. Ampelographic and ampelometric analyses, followed by molecular analysis, were carried out for varietal assessment. A rate of the grapes were fermented immediately after harvest with standard procedure, in comparison to rates vinified after withering. The latter was made in a greenhouse type structure with parts of natural and unforced air, without any additional energy expense. At the end of the process, a loss in weight of the grapes equal to 30–35% was realized. The grapes are then stemmed, crushed, pressed and fermented by selected yeast under controlled temperature. Upon completion of the fermentation and subsequent stabilization, the wines were analyzed for the most important enological parameters and subjected to evaluation by a panel of expert tasters. Chemical analysis of wines showed that an alcohol content ranging to 11–12% volume was reached with in the standard wine-making; whilst, for the vinification of dried grapes the alcohol content was equal to 16% vol for Mantonico bianco b. and 18% vol. for and Greco bianco. Organoleptic analysis of the wines showed a greater appreciation for both of dessert wines. The best ratings were given for the olfactory characteristics (floral and fruity aromas) and taste characteristics. In particular, the Greco bianco b. had excellent scores slightly lower than Malvasia di Lipari b. Therefore, the tested varieties have shown a good potential for the production of dessert wines related to typicality of the grape and the region. Dessert wines produced, have a complex flavor profile and interesting for the high acidic component, which improved the taste perception of wine and attenuated the sensation of sweetness. That feature could allow a good wine aging, too

Effect of sowing density and nitrogen top-dress fertilisation on growth and yield of chia (Salvia hispanica L.) in a Mediterranean environment: first results

The demand for sources of nutraceuticals has led to the rediscovery and diffusion of traditional crops such as chia (Salvia hispanica L.), whose leaves and fruits are rich in W3 fatty acids and anti-oxidants. Chia originates in Central America but it is rapidly expanding to new areas. A field experiment conducted at Atella in Basilicata (Southern Italy) was set up to test the response of chia to N top-dress fertilisation (0 and 20 kg ha–1) and to sowing density (D1=125, D2=25, D3=8 and D4=4 plants m–2) in a split-plot design with three replications. First results show maximum leaf area index values up to 7.1 and fresh vegetative biomass production at early flowering ranging between 50.87 (D4) and 59.71 (D1) t ha–1. Yield increased with plant density: a significantly (P<0.01) higher production (398 kg ha–1) was reached in D1. N top-dressing had a detrimental effect on yield and corresponded to higher lodging and lower maturation percentage of seeds, though non-significant. Based on our first results it seems worthwhile to continue agronomical trials for chia in herbaceous systems of southern Italy for leaf production based on traditional genotypes, while fruit production might be pursued by adopting high sowing density and the search for longer-day genotypes