Fruit Quality Evaluation Research Articles

Optical Methods for Quality Evaluation of Fruits (Part 2)

Optical Methods for Quality Evaluation of Fruits (Part 2)

Critical Comparison of an Accelerometer and a Laser Doppler Vibrometer for Measuring Fruit Firmness

To examine the feasibility of using a laser Doppler vibrometer (LDV) for fruit quality evaluation, measurements of firmness derived by this method were compared with those acquired using a contact accelerometer. Apples (Malus pumila Miller var. Domestica Schneider `Fuji'), kiwifruit [Actinidia deliciosa (A. Chev.) Liang et Ferguson, `Hayward'], Japanese pear [Pyrus pyrifolia (Burm. f.) Nakai var. Rehd. `Nijusseiki'], and Hassaku (Citrus hassaku Hort. ex Tanaka) were used. Fruit were subjected to sine waves at frequencies from 5 to 2000 Hz at the basal surface, and the vibrations resulting from these transmissions were precisely montitored at the upper surface with a LDV monitor. Measurements on all of the tested single fruit exhibited a distinct phase shift in the applied sine wave and in the responance frequency, dependent on frequency used. These shifts were also detected by an accelerometer, but in this case the range of frequency was restricted to an upper limit of 400 Hz for kiwifruit and 800 Hz for Japanese pear and Hassaku. Efforts to extend the range using a greater vibrational mass with the accelerometer resulted in anomalous tissue behavior, most likely due to excesive compression when the weight exceeded 1 g. Hence firmness measurements of fruit depended on the phase shift and resonance frequency, which were achieved with more precision by LDV than accelerometer. Since LDV measurements of fruit firmness were made without directly contacting the fruit surface, it could be potentially used for on-line quality evaluation and fruit sorting.

Nondestructive Quality Evaluation of Fruit and Vegetables by Acoustic Responses

Nondestructive Quality Evaluation of Fruit and Vegetables by Acoustic Responses

Texture of parenchymatous plant tissue: a comparison between tensile and other instrumental and sensory measurements of tissue strength and juiciness

Abstract The cellular basis of textural diversity in selected fruit and root tissue has been investigated using tensile measurements of tissue strength. The mechanism of tissue failure, either cell rupture or cell-to-cell debonding, was determined by examining the fracture surface using Low Temperature Scanning Electron Microscopy (LTSEM). Information provided by tensile measurements was compared with that provided by sensory and other instrumental measurements of tissue hardness and juiciness. Instrumental measurements included penetrometer, Kramer shear cell, apparent juice content, and juice release from a freshly cut surface. During tensile testing, the shape of the force-distance curve, along with maximum force and information on the cause of tissue failure were able to provide a comprehensive characterization of the texture. However, measurements of tensile strength, along with measurements of puncture strength and shear strength, showed a curvilinear relationship with sensory assessments of tissue hardness. This curvilinear relationship is fundamental to the psychophysical basis of human perception of texture. We speculate that the psychophysical laws that govern the relationship between mechanical hardness of a tissue and the associated sensory response may provide a major limitation to further improvements in the instrumental measurement of texture. We also discuss the use of instrumental measurements of juiciness to evaluate fruit quality.

Models of Ultrasonic Parameters to Assess Avocado Properties and Shelf Life

An ultrasonic testing technique was applied for non-destructive quality evaluation of avocado fruit and quantitative relations were established between ultrasonic parameters and maturity related factors. The fruits of the same batch and picking date softened at different storage times, a phenomenon which was attributed to different biological ages of the fruit at the picking date. Time-shifting of the test results of each fruit according to its firmness reduced the scatter of the experimental data. Second-order polynomial expressions represented well the changes in attenuation of the ultrasonic signals and the firmness of the fruit with storage time. A cubic equation represents fairly well the wave velocity of the ultrasonic signals versus time. A linear relationship was found between attenuation of the ultrasonic signal and firmness as measured in a cone penetrometer test. It was concluded that equations of this type may be used for prediction of ripening and shelf-life of avocado fruit, and could replace the commonly used penetrometer method. Further steps, such as the averaging of repeated measurements, may be needed to reduce scatter when predicting the maturity of individual fruits.

Evaluation of Fruit Quality of Apricot Cultivars and Selections

Four experimental apricot selections and four commercial apricot cultivars were evaluated for various physical and chemical characteristics. The eight apricot accessions were divided into three categories based upon their average dates of fruit maturation (based on flesh firmness) in California's San Joaquin Valley. Within maturity groups, apricot accessions evaluated in this study had diverse fruit weight, Brix, titratable acidity, and color of both flesh and skin. Profiles of volatile constituents extracted from the eight accessions did not follow any consistent pattern. Alcohols, however, were the dominant group of volatiles present in each sample, and linalool was highest within each profile. The results obtained from this research demonstrate that several of the experimental apricot selections had better fruit size, Brix and fruit color characteristics than commercial apricot cultivars of the same fruit maturity in the same ripening season.

Sensory Evaluation of Fruit Quality in an Apple Breeding Program

Overcoming bias in fruit quality evaluation is a challenge to fruit breeders, who must predict consumer preferences; databases of accurate fruit descriptions would be invaluable in helping them make selections to suit market needs. In order to obtain as informative a description as possible, plant breeding staff worked with sensory science personnel to define and quantify the appearance, flavor, and texture sensations they were experiencing when evaluating apples. Ten visual properties, nine flavor attributes, and nine texture characteristics were identified by evaluators; these were then clearly defined and reference materials representing the range of values found in apples were chosen as benchmarks. After screening and a brief training, nine people are now carrying out evaluations for the breeding project. In order to streamline the procedure, after two seasons of use the attributes are being examined for the usefulness in discriminating between genotypes.

Non-Destructive NIR Quality Evaluation of Fruits and Vegetables in Japan

Non-Destructive NIR Quality Evaluation of Fruits and Vegetables in Japan

樹上完熟栽培におけるウンシュウミカン果実のじょうのう膜の変化

Physico chemical characteristics of segment membranes were studied in 'Miyagawa Wase' and 'Hayashi Unshu' as related to delayed harvest. In this study, we focused on segment membrane strength because it may be a critical factor in evaluating fruit quality.1. Large fruits had thicker segment membranes than did small fruits in both cultivars. Segment membranes of developing fruits, while yet immature, became thinner in 'Miyagawa Wase' but thicker in 'Hayashi Unshu'. The membrane became thinner, however, in 'Hayashi Unshu' as the fruits matured.2. Intrusive resistance as an index of segment membrane strength was higher in larger fruits. With the advancement of maturation, it became lower in 'Miyagawa Wase', whereas it showed little or no changes in 'Hayashi Unshu'.3. Some morphological differences in cells of the segment membrane between the two cultivars were observed in late February. The inner epidermal surface of the segment membrane showed some cracking in 'Miyagawa Wase'. Cell size of the outer epidermis of the segment membrane was larger in 'Hayashi Unshu' than in 'Miyagawa Wase'. Some digestion of the cell membrane was found in the latter.4. Cellulase and polygalacturonase activity in segment membrane increased more rapidly in 'Miyagawa Wase' than it did in 'Hayashi Unshu' after November as the fruit ma- tured. Contents of cellulose and total pectic substances in the segment membrane per 100 g whole fruit fresh weight decreased rapidly after December. This tendency was more pronounced in the smaller fruits of 'Miyagawa Wase'. Cellulose content on a dry weight basis of alcohol insoluble solids (AIS), in segment membrane, was lowest in the smaller fruits of 'Miyagawa Wase'.We believe that changes in segment membrane strength are caused, not only by digestion of the segment membrane through degradation of cellulose and total pectic substances, but also by qualitative changes of the membrane itself through the decrease of cellulose content as determined by AIS.

Detecting Hollow Heart in Potatoes Using Ultrasound

An ultrasonic nondestructive evaluation system was developed and used for quality evaluation of fruits and vegetables. Ultrasonic waves at 250 kHz were transmitted through whole potato tubers to investigate the existence of hollow heart. Hollow heart in the potatoes was successfully detected. The waveform of transmitted ultrasonic signals through a hollow heart potato differed from that of a potato without hollow heart. Further, the defective tubers could be separated on the basis of the amount of ultrasonic power transmitted through a potato.

QUALITY EVALUATION OF CANTALOUPES FROM AHPID-INFESTED PLANTS

High populations of melon aphid (aphis gossypii) reduce cantaloupe plant growth and yield; effects on subsequent fruit quality are unknown. The purpose of this study was to evaluate fruit quality from plants with high and low aphid populations. Up to 50% of melons from plants having high aphid populations were unmarketable due to surface sooty mold. Melons from plants with high or low aphid populations, but not cultivars, were similar in flesh quality. The internal color of `Perlita' and `Sweet Surprise' was a more yellow hue while that of `TAM Uvalde' was more orange. `Sweet Surprise' melons were lower in percent soluble solids concentration and titratable acidity, but were higher in mg fructose/ml juice compared to the other cultivars. A trained taste panel of 30 people evaluated melons from 2 cultivars showing little damage from melon aphid infestations and from 2 cultivars exhibiting high damage. All melons had similar taste qualities with acceptable sweetness, flavor, odor and texture. These results show that high aphid populations deleteriously affect cosmetic appearance, but not flesh quality, of melons.

Delayed light emission as a means of quality evaluation of fruits and vegetables

DLE is probably produced by all fruits, vegetables, and plant materials undergoing photosynthesis. However, the intensity and duration of the emitted light vary widely depending upon many factors. Because of the strong dependence of DLE on the chlorophyll content, variation in the DLE can be expected among different varieties of the same product. Therefore, quality evaluation based on DLE measurements require careful selection of measuring criteria such as duration and intensity of illumination, dark period, and temperature. It is necessary to obtain precise values of DLE for a particular product under a set condition; and the measurement conditions should be carefully validated to establish a standard measuring criteria. In general, the quality evaluation of fruits and vegetables is based on three major aspects: maturity and/or ripeness evaluation, composition analysis, and internal and external defect detection. DLE measurements so far have focused mainly on maturity evaluation because of the definite relationship between the emitted light and chlorophyll concentration, which changes with maturity. It should be noted that chlorophyll alone is not sufficient; it is the complex of in situ chlorophyll and related compounds in plant materials that jointly contribute to the DLE. Composition of fruits such as sugar content has been related to DLE. Recently, DLE measurements have been applied to detect certain physiological stress responses and defects such as chilling injuries. However, these areas of research have not yet been fully explored. Further investigation relating to compositional quality and internal and external defects of fruits and vegetables with DLE measurement may offer solutions to certain complex quality evaluation problems. The duration of DLE after excitation involves a matter of at least several seconds. From a mechanical standpoint, this extended period of light emission offers a convenient time in which to separate excitation and measurement. However, the exponential decay necessitates very precise control of time between illumination and measurement. The broad activation spectrum permits wide choice and simple design of excitation sources. However, size, shape, and varietal variations of plant materials make uniform DLE measurements difficult. It is suggested that DLE measuring instruments be designed to make several measurements over the entire surface of the specimen. An average of such measurements would reduce the effect of surface nature and shape of the product. Reporting the DLE intensity per unit surface area of the product will eliminate the dependence of area of excitation on DLE.(ABSTRACT TRUNCATED AT 400 WORDS)

Evaluation of fruit quality in peach and apricot

The fruits of nine white-fleshed and three yellow-fleshed peaches, one white-fleshed nectarine and five apricot cultivars were compared as to chemical composition and sensory evaluation. Three acids (succinic, malic and citric) and eight sugars (xylitol, fructose, glucose, mannose, sorbitol, inositol, sucrose and maltose) were identified. The total amount (mg/100g FW) of acids ranged from 300 to 1,500 in peach and from 2,900 to 4,600 in apricot. The total amount of sugars ranged from 6,700 to 12,500 and from 7,400 to 10,800 for peach and apricot respectively. Total phenolics were very varia- ble, ranging from an average of 30 mg/100g FW in the yellow-fleshed peaches to values two-seven fold higher in the white ones and from 27 to 91 in apricots. According to the sensory and chemical evaluations conducted in this study, acceptable or good flavor should match the following composition (mg/100g FW). Peach: 1,000-1,600 organic acids, 8,500-13,000 alcohol- soluble sugars, 7.8-8.5 acid-sugar ratio; less than 80-90 phenolics. Apricot: 3,500-4,500 organic acids, 10-12,000 sugars, 2-3.5 sugar/acid ratio, less than 60 phenolics. The present study also suggests that sugar and acid patterns of fruit flesh may be useful in cultivar characterization.

NMR for Internal Quality Evaluation of Fruits and Vegetables

ABSTRACTNMR imaging can provide high resolution images of internal structures of fruits and vegetables and can be used for nondestructive evaluation of various internal quality factors, such as bruises, dry regions, worm damage, stage of maturity, and presence of voids, seeds, and pits. Experimental parameters have profound effects on image enhancement of specific features of the specimen..

青果物の電気的品質評価法に関する研究 Ｉ キウイフルーツのインピーダンス特性

青果物の電気的品質評価法に関する研究 Ｉ キウイフルーツのインピーダンス特性

Predicting Concentrations of Individual Sugars in Dry Mixtures by Near‐Infrared Reflectance Spectroscopy

ABSTRACTTo support research in nondestructive quality evaluation of fruits and vegetables, near infrared reflectance spectroscopy was used to measure concentrations of fructose, glucose, and sucrose in model systems intended to represent the major constituents of dried apple tissue. Spectra (950‐1850 nm) of a series of known samples were recorded, and multiple linear regression techniques were used to relate the concentrations of each sugar to reflectance measurements at selected wavelengths. Reflectance measurements at 3 computer‐selected wavelengths for each sugar were used to predict the concentrations in an independent set of samples. Correlation coefficients for actual vs predicted values were 0.995 for fructose, 0.994 for glucose, and 0.986 for sucrose, while the respective standard errors computed as variation from the regression lines were 1.48%, 1.39%, and 1.44%.

Nitrogen Fertilizer Requirements of Pickling Cucumbers Grown for Once-over Harvest I. Effect on Yield and Fresh Quality1

Abstract Different preplant and sidedress N fertilizer rates from NH4NO3 or urea were applied to pickling cucumbers (Cucumis sativus L.) grown for once-over harvest to determine the effect of N rate, source and time of application on cucumber yield, sex expression, and fruit quality. Nitrogen preplant rates of 67 or 134 kg/ha resulted in greater yields ($/ha and MT/ha) than no N preplant fertilizer. Preplant rates of 201 or 268 kg N/ha gave lower yields. The preplant source of N, NH4NO3 or urea had no effect on yield. Sidedress N as NH4NO3 or urea generally did not influence yields ($ and MT) when preplant N was used at rates of 67 or 134 kg/ha. The addition of preplant N fertilizer up to 134 kg/ha resulted in a slightly greater number of pistillate flowers per plant. The percentages of off-shape fruit were higher for the highest rate (268 kg/ha) of preplant N. Fruit quality evaluation (shape and color) and length:diameter ratios were generally not influenced by preplant N fertilizer.

The Biochemistry and Physiology of Ripening

Abstract The obvious changes which occur during ripening have long been the mainstay of man’s evaluation of fruit and vegetable quality. Influence of environment on these changes have been investigated over the past decade. More recently, research has focused on the basic physiological processes which occur prior to and in close association with the manifested ripening changes.

The Biochemistry and Physiology of Ripening

Abstract The obvious changes which occur during ripening have long been the mainstay of man’s evaluation of fruit and vegetable quality. Influence of environment on these changes have been investigated over the past decade. More recently, research has focused on the basic physiological processes which occur prior to and in close association with the manifested ripening changes.

Effect of Cultivation and Nitrogen Levels on Storage Quality, Yield and Color Grade of Starking ‘Red Delicious’ Apple Grown Under Grass Sod1

Abstract ‘Starking Red Delicious’ trees 15 years old on seedling rootstocks were fertilized with 5 levels of N as ammonium nitrate from 0.165 to 3.0 lb. per tree applied in a narrow band from 1961 to 1966 and cultivated at a shallow depth with a rotavator each year in March and May, March alone, or not at all. Evaluation of fruit quality at harvest time showed that there was no significant effect of N level or cultivation treatments on fruit color. Pressure test was reduced by the higher N treatments but soluble solids concentration was highest at the medium N applications. Titratable acidity was reduced by the higher N treatments but cultivation treatments had no effect. Flesh color of the fruit was the most sensitive of several tests made, higher N and more cultivation causing greener flesh. In tests at the end of storage life, pressure test and titratable acidity were still reduced by the higher N treatments. There was little effect on soluble solids, per cent rots or storage scald. Again, cultivation treatments had no effect. There was very little difference in yield among the N treatments except at the lowest levels of 0.5 and 0.165 lb. This effect was most marked with no cultivation. The N content of the leaves was increased by the N treatments from approximately 2.1% at the lowest level to approximately 2.4% at the highest level. There was no effect on terminal length or trunk circumference. It was shown that grass sod with or without moderate cultivation could largely override the effect of a very wide range of N levels. There was a deleterious effect only at very low N levels combined with no cultivation.