, had fruit with obvious differences in overall peel quality, the effect of sorting for fluorescing areas on the fruit was remarkably similar among the tests as can be seen by comparing the proportions of the various quality classes in each of the groups
(USDA) Plant Introduction (PI) 401734 produced significantly higher numbers of wild-type progenies ( Havey et al., 2004 ). A nuclear locus, Paternal sorting of mitochondria ( Psm ), controls sorting to the wild-type phenotype in progenies from crosses
Abstract
A method is described and test results reported for sorting blueberries with low-frequency vibration. Separation was dependent on fruit firmness which is affected by roughness of handling and other softening factors.
Firmness, as measured by compressing blueberries 0.2 cm between flat plates, statistically explained 58 to 72% of the variation in frequency for removal of berries from a vibrating trough with constant energy input. When comparing ripeness with frequency for sorting, light transmittance (∆OD; 740-800 nm) values, which indicate anthocyanin pigment concentration, explained only 10% of the variation in sorting frequency.
Berries of several cultivars and harvest dates were vibration sorted and tested for susceptibility to decay. Sorting frequency statistically explained 75% of the variation in decay level. Thus, the vibration method should be suitable for sorting blueberries into groups of different shelf life.
( Steckel et al., 1989 ; Ward et al., 1992 ). Chlorophyll in white-seeded Phaseolus vulgaris seeds is visible and may be detected and sorted by color-sorting seed conditioning equipment ( Lee et al., 1998 ). Another non-destructive technique for assessing
Abstract
Green fruits of tomato (Lycopersicon esculentum Mill.) of 4 different cultivars, including 2 having the crimson fruit character (ogc ), were sorted photometrically into 2 sub-samples of comparable maturity. One subsample was treated with ethylene gas and the ripening behavior of both was followed. The photometric sorting technique was superior to visual classification in providing uniform fruit maturity classes of the crimson-type fruit. These fruit responded normally to ethylene ripening when compared to standard cultivars.
Abstract
Researchers working with strawberries often find it necessary to size, grade, count, and weigh the fruit (1, 2, 3, 4). These tasks present problems when the research involves a large number of test plots. Size-yield classifications of hand-sorted fruit are not only time-consuming, but are subject to human error. A strawberry sorter for research use was developed to reduce these problems.
Abstract
Spectral curves of fresh berries of both bronze and black muscadine grapes representing a wide range of ripenesses were obtained with a multipurpose spectrophotometer at the Pioneering Instrumentation Laboratory of the U.S. Department of Agriculture at Beltsville, Md. Using these curves, wavelength-pairs of 546-610 nm for bronze and 740-800 nm for black grapes were selected. A Berrymatic (high-speed fibre-optic sorter) developed for sorting blueberries was fitted with pairs of narrow band interference filters of the above wavelengths. Several tests over a 2-year period indicated that both black and bronze grapes can be light-sorted according to ripeness, as confirmed by destructive analyses of pH, soluble solids and acids in the fruits. Berry size and orientations of the berry on the light-sorter with respect to the light path influenced readings.
Chloroplast fluorescence as a nondestructive tool for assessing `Red Delicious', `Golden Delicious' and `Law Rome' apple fruit quality was examined after approximately 4.5 months storage. Fluorometry parameters of minimal fluorescence (Fo), maximal fluorescence (Fm) and quantum yield (Fm-Fo)/Fm (otherwise denoted as Fv/Fm) were determined. All fluorescence parameters declined with time as apple fruit were maintained at 22°C in air. Fv/Fm was found to correlate well with firmness for `Red Delicious' fruit. A decline in Fo with time correlated very well with the development of yellow coloration of `Golden Delicious' fruit. The Fv/Fm value was consistently higher for controlled-atmosphere (CA) stored fruit than for regular-air (RA) stored fruit. When CA and RA stored `Law Rome' fruit were combined and a Fv/Fm value of 0.685 was used to resegregate fruit from the two storage regimes. Resegregation was achieved with 75% accuracy, with only 5% RA-stored fruit incorrectly identified as CA-stored. The accuracy, speed of assessment and light-based nature of fluorometry suggest it may have some practical use as a tool for sorting apple and other chlorophyll-containing fruit on commercial packinglines.
Color sorting was performed to upgrade seed quality by removal of fluorescent coated seeds. The fluorescent coating was attributed to sinapine leakage from nonviable seeds. Nine seedlots, three seedlots each of cabbage (Brassica oleracea L. Capitata group), broccoli, and cauliflower (B. oleracea L. Botrytis group) were custom coated. Seed samples were pretreated before coating with or without 1.0% NaOCl for 10 minutes to enhance leakage. All samples revealed a percentage of seeds with fluorescence. The light emission from selected fluorescent and nonfluorescent coated seeds was quantified by fiber-optic spectrophotometry. Fluorescence was expressed from 400 to 560 nm, with peak emission being from 430 to 450 nm. These data confirmed our visual interpretation of blue-green fluorescence. The ratio of light emission from fluorescent compared to nonfluorescent coated seeds ranged from 4.5 to 7.0 for all samples and averaged 5.7. An ultraviolet (UV) color sorter was employed to separate fluorescent (reject) from nonfluorescent (accept) coated seeds. The percentage of nonfluorescent coated seeds (averaged over seedlot and NaOCl pretreatment) before and after sorting was 89.5% and 95.9%, respectively. Therefore, color sorting was able to remove a high percentage of fluorescent coated seeds with an average loss (rejection of nonfluorescent coated seeds) of 6%. An increase in the percent germination was recorded in eight of the nine seedlots following color sorting, and the greatest improvement was obtained with seedlots of medium quality. Germination of three medium quality lots was increased by 10 to 15 percentage points. The average increase in germination with or without NaOCl pretreatment was 8.2 and 5.5 percentage points, respectively. In conclusion, the germination of Brassica seedlots could be improved by separating (removing) fluorescent from nonfluorescent coated seeds. UV color sorting technology was employed to demonstrate that seed conditioning could be conducted on a commercial basis to upgrade seed quality.
We have developed an electronic sensor (“sniffer”) that measures fruit ripeness rapidly and nondestructively by measuring the aromatic volatiles that are naturally emitted by ripening fruit. In this study, we evaluated the potential of using the fruit ripeness sniffer in the quality sorting of blueberries. Blueberries were first visually classified into four distinct ripeness classes: unripe; half-ripe; ripe; and over-ripe and quantitatively measured for color, firmness, TSS, and sugar acid ratio. Ripeness classification accuracy with the sniffer matched or exceeded that of all other ripeness indices. The sniffer differentiated unripe, ripe and over-ripe berries within one second, but could not distinguish between the unripe and half-ripe class. Detection of l-2 damaged or 1-2 soft fruit spiked within a large container of 24-37 high quality ripe fruit was also achieved, but required a response time of 10 seconds. Electronic sensing of aromatic volatiles may be a useful new technique in the grading and sorting of blueberries.