Measurement of impact pressure and bruising of apple fruit using pressure-sensitive film technique

Impact pressure and bruising of apple fruit were measured by means of a pressure-sensitive film technique, in order to develop methods for assessing and predicting bruising of apples resulting from impact loads during the course of transport and handling. Results of impact tests with apples indicate that when the fruits are dropped from different heights onto different impacting surfaces, the bruise area and volume could be assessed and predicted by regression models based on the impact force obtained from the pressure-sensitive film (FPSF). The coefficients of determination (R2) for bruise area and bruise volume were found to be 0.91 and 0.95, respectively

Development of methods to estimate or reduce pressure flattening of potatoes during storage

2013 Spring.Includes bibliographical references.To view the abstract, please see the full text of the document

Comparison of the mechanical fatigue indices of Golden Delicious apples and Packham pears

One of the most significant phenomena in the processing of horticultural crops, leading to the damaging of the fruit, is fatigue due to repeated mechanical stress, which endangers the integrity of the produce, especially during transport. In the event of such damages, the immediate environment of the damaged fruit, or even the entire batch of crops may be in danger, as the biological processes leading to spoilage are not limited to the individual crop damaged. In the case of repeated effects, a force less than the static limit value is sufficient to cause spoilage, but in addition to the load, the material properties of the given crop, as well as the energy balance observed during damage play important roles in determining the mechanical resistance. Accordingly, in our work, a description of the spoilage process is built on the material models most characteristic of the selected crops, on the dissipated energy indicators measured during repeated loads, and on the definition and determination of the spoilage time. In the experiments, the fatigue indices of Golden Delicious apples, making up most of the apple production of the European Union, and of long shelflife Packham pears are compared by setting up linear regression models

Optimising the Postharvest Management Of Lychee (Litchi chinensis Sonn.) - A Study of Mechanical Injury and Desiccation

The major objective of the research was to improve lychee postharvest management, through a greater understanding of mechanical injury and moisture loss. Mechanical injury is a known cause of postharvest loss in lychee, but previously published information has been limited to broad observations. In this study, the symptoms of mechanical damage in lychee were defined, including quantitative measurement of colour changes. Impact injury caused protuberance tip darkening, cracking of the pericarp and significant changes in skin colour. Compression also typically caused tip darkening, and severe loads were capable of puncture, shape distortion and skin cracking. Abrasion and vibration injuries were characterised by strong yellowing of pericarp colour, possibly due to the leakage of cell contents onto the fruit surface. Vibration also caused significant darkening and loss of colour saturation. Vibration has not previously been mentioned as an issue in lychee postharvest management, but appeared to be as important a problem as desiccation browning at the wholesale level, both in incidence and severity. Mechanically damaged fruit consistently showed increased ethylene and carbon dioxide synthesis, and moisture loss was increased by up to 30%. Some significant changes in skin biochemistry and cuticle properties were also detected. The study of damaged tissue by SEM revealed distinctive patterns of surface tissue disruption. Open pericarp cracking was a particularly detrimental injury, causing significantly increased electrolyte leakage and rapid pathogen development. The effects of load characteristics, such as magnitude, method of application, site, repetition and cushioning, on the extent of damage were defined. Fruit characteristics such as cultivar, gross morphology, temperature, hydration and surface wetness were shown to significantly affect damage levels. Small seed size was correlated with increased cracking susceptibility. Fruit surface wetness exacerbated vibration or abrasion damage. Turgid fruit were less susceptible to vibration and abrasion damage, but showed increased susceptibility to impact cracking. Previously neglected aspects of desiccation browning research were studied, including cultivar and maturity effects, sites of moisture loss and the role of air currents. Cultivar effects on moisture loss were obscured by pre-harvest factors, but consistent cultivar differences were detected in desiccation browning, possibly related to skin thickness. In contrast, maturity levels over a marketable range had little effect on weight loss or browning. Moisture was lost fairly evenly over the fruit surface, but poor postharvest handling appeared to massively increase loss from the protuberance tips. Moisture loss was shown to substantially increase ethylene synthesis. The crucial role of air currents in exacerbating lychee moisture loss was emphasised, and the relationship between air speed and weight loss was defined. The research contributed to a greater understanding of the processes of mechanical damage and moisture loss in lychee, leading to improved protocols for the postharvest management of the fruit. Improved management of mechanical damage and moisture loss will ultimately improve fruit quality and reduce postharvest losses, hence increasing returns to industry

Optimising the Postharvest Management Of Lychee (Litchi chinensis Sonn.) - A Study of Mechanical Injury and Desiccation

The major objective of the research was to improve lychee postharvest management, through a greater understanding of mechanical injury and moisture loss. Mechanical injury is a known cause of postharvest loss in lychee, but previously published information has been limited to broad observations. In this study, the symptoms of mechanical damage in lychee were defined, including quantitative measurement of colour changes. Impact injury caused protuberance tip darkening, cracking of the pericarp and significant changes in skin colour. Compression also typically caused tip darkening, and severe loads were capable of puncture, shape distortion and skin cracking. Abrasion and vibration injuries were characterised by strong yellowing of pericarp colour, possibly due to the leakage of cell contents onto the fruit surface. Vibration also caused significant darkening and loss of colour saturation. Vibration has not previously been mentioned as an issue in lychee postharvest management, but appeared to be as important a problem as desiccation browning at the wholesale level, both in incidence and severity. Mechanically damaged fruit consistently showed increased ethylene and carbon dioxide synthesis, and moisture loss was increased by up to 30%. Some significant changes in skin biochemistry and cuticle properties were also detected. The study of damaged tissue by SEM revealed distinctive patterns of surface tissue disruption. Open pericarp cracking was a particularly detrimental injury, causing significantly increased electrolyte leakage and rapid pathogen development. The effects of load characteristics, such as magnitude, method of application, site, repetition and cushioning, on the extent of damage were defined. Fruit characteristics such as cultivar, gross morphology, temperature, hydration and surface wetness were shown to significantly affect damage levels. Small seed size was correlated with increased cracking susceptibility. Fruit surface wetness exacerbated vibration or abrasion damage. Turgid fruit were less susceptible to vibration and abrasion damage, but showed increased susceptibility to impact cracking. Previously neglected aspects of desiccation browning research were studied, including cultivar and maturity effects, sites of moisture loss and the role of air currents. Cultivar effects on moisture loss were obscured by pre-harvest factors, but consistent cultivar differences were detected in desiccation browning, possibly related to skin thickness. In contrast, maturity levels over a marketable range had little effect on weight loss or browning. Moisture was lost fairly evenly over the fruit surface, but poor postharvest handling appeared to massively increase loss from the protuberance tips. Moisture loss was shown to substantially increase ethylene synthesis. The crucial role of air currents in exacerbating lychee moisture loss was emphasised, and the relationship between air speed and weight loss was defined. The research contributed to a greater understanding of the processes of mechanical damage and moisture loss in lychee, leading to improved protocols for the postharvest management of the fruit. Improved management of mechanical damage and moisture loss will ultimately improve fruit quality and reduce postharvest losses, hence increasing returns to industry

Mealiness Detection in Agricultural Crops: Destructive and Nondestructive Tests: A Review

Mealiness is known as an important internal quality attribute of fruits/vegetables, which has significant influence on consumer purchasing decisions. Mealiness has been a topic of research interest over the past several decades. A number of destructive and nondestructive techniques are introduced for mealiness detection. Nondestructive methods are more interesting because they are rapid, noninvasive, and suitable for real-time purposes. In this review, the concept of mealiness is presented for potato, apple, and peach, followed by an in-depth discussion about applications of destructive and nondestructive techniques developed for mealiness detection. The results suggest the potential of electromagnetic-based techniques for nondestructive mealiness evaluation. Further investigations are in progress to find more appropriate nondestructive techniques as well as cost and performance

Postharvest Handling of Horticultural Crops

The postharvest handling of horticultural produce is of major importance because fresh fruit and vegetables are highly perishable. It is estimated that 30% of produced horticultural commodities are lost in processes between harvest and consumption, and the reduction in these losses is currently imperative because it will impact the amount of produced food, introducing benefits on agricultural inputs, water, and land use and contributing to the sustainability of agriculture and the planet. The Special Issue “Postharvest handling of horticultural produce” collects a series of recent research papers focusing on the ripening of fruit and the senescence of harvested horticultural products, in addition to the development of environmentally friendly products and technologies that positively impact the quality and shelf life of those products, improving consumers’ preference. This Special Issue provides a valuable contribution for understanding horticultural products’ postharvest physiology and the implementation of new innovative technologies for reducing quality loss through the supply chain. In this manner, this Special Issue contributes to reductions in food loss, promoting the sustainability of agriculture

The non-invasive assessment of avocado maturity and quality

Horticultural products in today's modern market must have high quality standards. Consumer demand for consistent quality agricultural produce remains strong and continues to increase, this will lead to the development and subsequent increased availability of sophisticated techniques, sensors, and user-friendly non-invasive systems for measuring product quality indices. The inability to consistently guarantee internal fruit quality is a major factor not only for the Australian avocado industry but also the entire horticulture sector. Poor fruit quality is seen as a key factor affecting consumer confidence and impacts on supply chain efficiency and profitability. Removing fruit quality inconsistencies while providing the consumer with a consistent quality product is a vital commercial consideration of the Australian avocado industry for both domestic and export markets. Many fruit quality attributes affecting consumer acceptance are assessed using traditional methods that are generally subjective, labour intensive and costly. Commercially, avocado maturity is measured destructively by the determination of dry matter (DM) content, moisture content (MC) or oil content, all of which are highly correlated. Maturity is an important component in avocado fruit quality and a prime factor in palatability. A rapid, non-destructive measurement system that can accurately and simultaneously monitor external and internal attributes of every avocado fruit either in the field or in an in-line setting, is highly desirable for ensuring consistent product quality over an extended season, increasing industry marketability and profitability. The utility of near infrared (NIR) spectroscopy was investigated as a non-invasive assessment tool for estimating avocado maturity and thereby eating quality based on dry matter content of whole intact fruit primarily for the avocado variety 'Hass'. The technique was also assessed for detecting bruises and for predicting rot susceptibility as an indication of shelf-life for possible implementation in a commercial in-line application. The project also investigated the importance of the calibration model development process to incorporate seasonal and geographical variability to ensure model robustness. NIR spectroscopy has an obvious place in agriculture and environmental applications with its core strength in the analysis of biological materials, plus low cost of analysis, simplicity in sample preparation, no chemical reagent requirements, simultaneous analysis of multiple constituents, good repeatability and high throughput capability. The commercially available NIR spectroscopy systems assessed in this project highlighted the potential of NIR spectroscopy and its suitability for application in a commercial in-line setting for predicting avocado maturity and palatability of whole intact avocados, based on DM content. With horticultural products, the major challenge of implementing NIR spectroscopy is to ensure that the calibration model is robust, that is, that the calibration model holds across growing seasons and potentially across growing districts. The present project represents the first study to investigate the effect of seasonal variation on model robustness to be applied to avocado fruit. It found that seasonal variability has a significant effect on model predictive performance for DM in avocados. The robustness of the calibration model, which in general limits the commercial application for the technique, was found to increase across seasons when more seasonal variability was included in the calibration set. Across the seasons it achieved predictive performances in this case in the range of: validation coefficient of determination (Rᵥ²) of 0.76 – 0.89, root mean square error of prediction (RMSEP) of 1.43 - 1.97%, and standard deviation ratio's (SDR) of 2.0 to 3.1. Similarly, there are spectral differences between geographical regions and that specific regional models may have significantly reduced predictive performance when applied to samples containing biological variability from a different growing region. As with seasonal variability, this can be addressed by incorporating multiple geographical growing regions into the calibration model to account for the biological variability to improve model robustness as demonstrated in this study (i.e., Rᵥ² of 0.89, RMSEP of 1.51%, and SDR of 3.6). Furthermore, when models are constructed to include both season and geographical variability, model performance can be more robust when dealing with a broader range of future sample variability. This was demonstrated with calibration models constructed to incorporate 3 years of seasonal variability and encompassing 3 geographical regions, obtaining predictive performances ranging from Rᵥ ² 0.87 - 0.89; RMSEP of 1.42 - 1.64% and SDR of 2.7 - 3.1 across the various geographical regions. NIR spectroscopy shows great promise for the application in a commercial, in-line setting for the non-destructive evaluation of impact damage (bruising) and rot susceptibility of whole avocado fruit, although optimisation of the technology is required to address speed of throughput and environmental issues. The adoption of a rapid, non-invasive method to identify fruit that are less prone to rots and internal disorders would allow selection of fruit that could be sent to more distant markets with greater confidence that it will arrive in acceptable quality, thus ensuring maximum yield and higher returns for the producer and marketer. The ability of the NIR classification models to accurately predict rot development of hard green avocado fruit (stage 0 ripeness) into two classes, ≤10% and >10% of flesh affected, ranged from 65-84% over the three growing seasons. When the rot classes were defined as ≤30% and >30% the accuracy ranged from 69%-77%. In relation to impact damage (bruising), trials conducted over three growing seasons using an NIR spot assessment technique found hard green fruit at stage 2 ripeness, that were deliberately bruised could be correctly detected with 70-79% accuracy after 2-5 hours of impacting and with 83-89% accuracy after 24 hours. For eating ripe (stage 4) fruit, the accuracy was 60-100% after 2-5 hours of impacting and 66-100% after 24 hours across the three growing seasons. This indicates that in a commercial situation it would be an advantage to hold the fruit for 24 hours before undertaking NIR scanning

ADVANCEMENT IN HARVESTING, PRE- COOLING AND GRADING OF FRUITS.

Generally, quality grading includes outer parameters (size, color intensity, color homogeneity, bruises, shape, stem identification surface texture and mass), inner parameters (sweetness, acidity or inner diseases) and freshness. All horticultural crops are high in water content and are subjected to desiccation and to mechanical injury. That is why these perishable commodities need very careful handling at every stage so that deterioration of produce is restricted as much as possible during the period between harvest and consumption.  Horticultural maturity is the stage of development when plant and plant part possesses the pre- requisites for use by consumers for a particular purpose i.e, ready to harvest. Post harvest handling is the final stage in the process of producing high quality fresh produce. Being able to maintain a level of freshness from the field to the dinner table presents many challenges. A grower who can meet these challenges will be able to expand his or her marketing opportunities and be better able to compete in the market place. Â