Relationship between nondestructive firmness measurements and commercially important ripening fruit stages for peaches, nectarines and plums (original) (raw)
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TELKOMNIKA (Telecommunication Computing Electronics and Control)
The evaluation of internal condition of the fruit via destructive techniques mostly damaged the internal and external fruit structure. However, there are several non-destructive techniques available could be applied in the agricultural industry, specifically for observing internal fruit conditions. Different kinds of internal conditions of fruits are evaluated in terms of their quality and ripeness levels. These nondestructive techniques include fruit evaluation via ultrasonic measurement techniques, light spectroscopy, imaging via Magnetic Resonance Imaging (MRI) and X-Ray, computer vision, electric nose and also vibration. The capabilities and the effectiveness of these techniques towards fruit monitoring are thoroughly discussed. Besides, the drawback of these non-destructive technique has been analysed.
Non-destructive quality measurement and modelling in fruits
A European Project entitled 'Quality of fruits: Engineering research for improving the quality preservation during pre-and postharvest operations' is being carried out by six European research Institutions. Relevant aspects of quality of fresh fruit in the European market are investigated. Firmness sensing of selected varieties of apples, pears and avocado fruits has been developed using a non-destructive impact technique. In addition to firmness measurements, postharvest ripeness of apples and pears was monitored by spectrophotometric reflectance measurements, and that of avocadoes by Hunter colour measurements. The data obtained from firmness sensing were analysed by three analytical procedures: Principal Components, Correlation, and Stepwise Discriminant Analysis. A new software was developed to control the impact test, analyse the data, and sort the fruit into specified classes, based on the criteria obtained from a training run. Similar procedures were used to analyse the reflectance and colour data. Both sensing systems were able to classify fruits with good accuracy. An automatized prototype of on-line classifier has been built.
Use of Non-Destructive Devices as a Decision Support System for Fruit Quality Enhancement
EUFRIN Thinning Working Group Symposia, 2013
Fruit quality as a concept encompasses sensory and mechanical properties, nutritive values and food safety. Fruit quality has declined, leading to consumer dissatisfaction, largely due to the wrong harvest date. In addition, quality is poorly defined since the parameters mainly considered are fruit size and skin colour. Other attributes such as flesh firmness, sugar content, acidity and aroma, which are perceived by the consumer as overall fruit quality, are seldom considered by the farmer and by other individuals along the value chain. Up to now, several studies have been carried out on fruit quality assessment by using traditional methods, which are cheap and fast, but do not consider other quality traits, as antioxidant power, aroma volatile emission, soluble sugars and organic acids content. The assessment of these parameters requires sophisticated equipments (i.e. HPLC, GC-MS) and is costly and time consuming. Moreover, destructive analyses can be performed only on a limited number of fruit. In recent years, extensive research has been focused on the development of non-destructive techniques for assessing internal fruit quality attributes allowing extending the assessment to a high number of fruit, to repeat the analysis on the same samples and to achieve real-time information on several fruit quality parameters at the same time. Among the non-destructive techniques, visible/Near infrared spectroscopy (VIS/NIR) can be efficiently used for determining traditional fruit quality traits and concentration of the main organic acids and reducing sugars. In addition, this technique allows defining a new maturity index with a close correlation to fruit ethylene emission and ripening stage. This "Absorbance Difference" Index (I AD) can be used for precisely predicting harvest date and for grouping fruit in homogeneous classes of ripening.
The Use of Non-destructive Methods to Analyse Fruit Quality
This article is divided into three parts. The first part, the most important one, deals with spectroscopic methods. Different regions of the electromagnetic spectrum are useful for fruit quality characterisation, in particular the visible and near-infrared regions. Concerning the visible one, studies have been carried out on apple, apricot, cherry, mango, peach, red table grape and tomato, when the near-infrared one has been used on apple, apricot, bayberry, citrus, kiwi, lemon, mango, peach, pear, red bell pepper and tomato. Results of other spectroscopic methods such as time-domain reflectance spectroscopy, multi-and hyperspectral imaging, fluorescence, nuclear magnetic resonance and magnetic resonance imaging were obtained on apple, grape berry, kiwifruit, mandarin, olive, papaya, peach, pear, plum and tomato. The second part concerns the studies of mechanical properties based on impact, acoustic and ultrasonic responses, which were developed and tested on apple, avocado, peach, pear, plum, tomato and watermelon. The third part presents the analysis of volatile compounds using the principle of electronic nose applied on apple, mandarin, peach, pear and tomato. According to the researched fruit quality traits, the adequate methods will be different for the assessment of colour, firmness, soluble solids or volatiles or for the detection of internal defects like brown heart. However, methods are developed to improve the fruit management and thus the general fruit quality for consumers.
Biosystems Engineering, 2009
Measurements of firmness have traditionally been carried out according to the Magness Taylor (MT) procedure; using a texture analyser or penetrometer in reference texture tests. Non-destructive tests like the acoustic impulse response of acoustic firmness sensors (AFSs), a low-mass impact firmness sensor Sinclair International (SIQ-FT) and impact test (Lateral Impact-UPM) have also been used to measure texture and firmness. The objectives of this study were to evaluate the influence of different sources of variation in these three non-destructive tests and to evaluate their respective capabilities of discriminating between fruit maturity at two different harvest dates, turgidity before and after dehydration treatment and ripening after different storage periods. According to our results, fruit studied an unexpected AFS trend with turgidity. Contact measurements (Lateral Impact-UPM and SIQ-FT) appeared highly sensitive to changes in turgidity, but were less able to follow changes in ripening caused by storage period. Contact measurements were suitable for detecting differences between fruits from different harvest dates and showed higher correlation coefficients with reference texture tests than acoustic measurements. The Lateral Impact-UPM test proved better at separating fruits according to turgidity than the SIQ-FT instrument.
Methods to Assess Fruit Quality Focusing on Non-Destructive Methods
XV International Symposium on Apricot Breeding and Culture, 2012
In apricot (Prunus armeniaca), fruit quality at consumption and shelf-life potential are strictly related to the ripening stage at harvest. Although establishing the optimal harvest time is a crucial issue, this is normally performed on the basis of fruit size, skin color and grower experience. The internal quality traits, such as flesh firmness (FF), soluble solids content (SSC), titrable acidity (TA) and aroma are commonly used to evaluate fruit quality and ripeness. However, these parameters which are perceived by the consumer as fruit global quality are seldom considered. Up to now, several studies have been carried out on fruit quality assessment by using traditional methods, which are cheap and fast, but do not consider other quality traits, as antioxidant power, aroma volatile emission, soluble sugars and organic acids content. To better characterize fruit quality, extensive research has been focused on the development of non-destructive techniques, in particular on visible/Near Infra Red spectroscopy (vis/NIRs) that can be efficiently used for determining traditional fruit quality traits and concentration of the main organic acids and sugars. In addition, this technique allows to define a new maturity index, called Index of "Absorbance Difference" (I AD), strictly related to fruit ethylene emission and ripening stage. The I AD was used to establish, in field conditions, the optimal harvest time related to the ripening stage at harvest and to characterize fruit ripening as affected by bearing shoots, fruit position on the tree in order to decide the best training system and pruning techniques to reduce fruit ripening heterogeneity on the tree. Here is reported on the research activity carried out on apricot cultivars grown in Valais (Sion, Switzerland). The obtained results showed that the I AD was able to group fruit according to their ripening stage. Fruit graded according the I AD were used for a consumer test to verify their acceptance.
'Carabao' mango was harvested green at different stages of maturity [100, 105, 110, 115, 120 and 125 d after flower induction (DAFI)] and subjected to nondestructive firmness test using a universal testing machine. A 7.9-mm diameter plunger with rounded tip (6.9-mm radius of curvature) was pressed onto whole fruit at 10 mm min-1 crosshead speed, to produce deformations of 0.8, 1.3, and 1.8 mm; additional fruits were tested until rupture for comparison. Total soluble solids (TSS), titratable acidity (TA) and pH were measured at the green stage and at the table-ripe stage (TRS) after ripening at 25 °C. Sensory analysis was performed at TRS to determine the best harvest maturity. Results showed no significant differences in TSS, TA and pH between maturities at the green stage; hence, physico-chemical properties could not be used to test for maturity. Sensory analysis at TRS showed that fruit harvested at 115–120 DAFI gave the best eating quality in terms of aroma, sweetness, sourness, flavor and overall acceptability. Fruits harvested at 125 DAFI showed significantly lower sensory scores. Significant differences in rupture force (F R , kN) and fruit stiffness (B, kN mm-1 of deformation) were observed between maturities at the green stage; however, the nondestructive deformation test at 0.8 mm was more sensitive to fruit maturity. Fruits harvested at 115–120 DAFI had significantly lower values for B and load ratio at 0.8-mm to 0.5-mm deformation (F 0.8 /F 0.5) compared with earlier harvest dates. Analysis of the normal distribution curve of a prediction set of 40 mature (MAT) fruits showed that 80% of the samples had B ≤ 1.360 kN mm-1 and F 0.8 /F 0.5 ≤ 1.883. Based on the use of signal detection theory and these values as thresholds, 66.3% (by B) and 58.8% (by F 0.8 /F 0.5) of immature or overmature (I/O) fruit could be detected. Analysis of a separate validation set of fruit using the same threshold values gave respective detection rates of I/O fruit of 68.8% using B and 60.0% using F 0.8 /F 0.5 .