Lower Soluble Solids Content Research Articles

Juice Quality of `Valencia' Sweet Oranges Borne on Different Inflorescence Types

The objectives of this study were to determine whether juice quality of `Valencia' sweet orange [C. sinensis (L.) Osb.] is affected by the type of inflorescence on which fruit are borne, and to determine the contribution of inflorescence type to within-tree variation in juice quality. During the 1998-99 and 1999-2000 seasons, fruit size and juice quality [soluble solids concentration (SSC) and titratable acidity (TA)] of fruit from `Valencia' sweet orange trees on Carrizo citrange rootstock [Poncirus trifoliata (L.) Raf. × C. sinensis (L.) Osb.] planted in 1987 at Howey-in-the-Hills, Fla., were measured. A 2×2 factorial design (inflorescence type × canopy position) with leafy and leafless inflorescence types, and southwest top and northeast bottom canopy positions was used. The type of inflorescence on which fruit were borne had a minor effect on juice quality, and inflorescence type and juice quality were not directly associated. Rather, juice SSC was associated with the effect of inflorescence type on fruit size, as small fruit tended to have higher SSC than large fruit, regardless of the type of inflorescence on which fruit were borne. The relatively small difference in SSC between fruit borne on leafy and leafless inflorescences (≈3% of mean SSC) was an indirect result of fruit size. Therefore, fruit borne on leafy inflorescences, which tend to be of larger size compared with fruit borne on leafless inflorescences, tended to have marginally lower SSC. Acid content and ratio of SSC: TA were not related to inflorescence type. In addition, the type of inflorescence on which fruit were borne made only a nominal contribution to variability in juice SSC, in contrast to the major contribution of canopy position to within-tree variation in juice SSC. Factors other than inflorescence type are important components of within-tree variation in juice SSC.

Effects of exogenous putrescine on improving shelf life of four plum cultivars

Abstract Four plum cultivars (‘Golden Japan’, ‘Black Diamond’, ‘Black Star’ and ‘Santa Rosa’) were treated with 1 mM putrescine, and then stored at 20 °C. Storage duration was different for each cultivar, but the effect of putrescine in terms of increased shelf life, delayed ripening process, and higher quality attributes when compared with controls was significant for all cultivars. In addition, putrescine-treated plums showed delay and/or reduction on ethylene production, the intensity of reduction being dependent on the maximum of ethylene production at the climacteric peak. Also, higher fruit and flesh firmness, lower soluble solids concentration and titratable acidity evolution, reduced weight loss and delayed colour changes were found after putrescine treatment during storage. Moreover, higher putrescine and spermidine levels (free forms) were observed in putrescine-treated plums. The results revealed that plum storability could be extended by putrescine treatment due to its effect on delaying the ripening processes.

Yield and Quality of Triploid Watermelon Cultivars and Experimental Hybrids Grown in Mississippi

Evaluations of 21 entries (commercial cultivars and breeders' experimental hybrids) of triploid watermelon (Citrullus lanatus) were conducted in northern and central Mississippi during 2000 and 2001. The purpose of this research was to identify high-yielding, medium-sized triploid cultivars with good horticultural characteristics and consumer qualities for commercial production in Mississippi. Most entries were similar to `Tri-X 313' and had red flesh, oval shape, and a mottle stripe rind pattern. SXW 5052, `Triple Crown,' `Crimson Trio,' `SeedWay 4502,' and `Millionaire' produced the highest total marketable yields; however, SXW 5052 is no longer available. `Crimson Trio' produced slightly smaller-sized melons compared to other entries and `SeedWay 4502' produced melons with relatively low soluble solids concentration. Based on total marketable yield, average size of melons, soluble solids concentration, and lack of undesirable characteristics such as hollowheart, black and colored seed, and rind necrosis, `Triple Crown,' `Millionaire,' `Cooperstown,' `Summer Sweet 5244,' and `Crimson Trio' can be recommended as mid- to late-maturing cultivars for commercial production in Mississippi. Based on early marketable yield, and using the same criteria listed above, `Tri-X 313' and `Tri-X Carousel' can be recommended as early-maturing cultivars for commercial production in Mississippi. `Tri-X 313' exhibited only one undesirable trait, producing a relatively high number of black and colored seeds. `Diamond' had high early and total yields, as well as high soluble solids concentration, but it should be recommended only on a trial basis to determine its potential susceptibility to hollowheart.

Rain Protective Covering of Sweet Cherry Trees—Effects of Different Covering Methods on Fruit Quality and Microclimate

Three different rain protective covering methods for sweet cherry (Prunus avium) trees were tested with uncovered trees as control. The covers were a pitched cover mounted permanently, a similar cover mounted only when raining, and a permanent umbrella type enveloping the top and sides of single trees. Covers were mounted 3 weeks before and throughout the harvest period in two seasons with different weather conditions. All three covering methods increased the amount of marketable fruit from 54% on uncovered to 89% on covered trees in mean of 2 years. Fruit from umbrella covered trees had lower soluble solid content, lower juice color and lower ripeness compared with fruit from all other trees, reflecting the different microclimate in these trees such as frequently higher maximum temperatures and greater vapor pressure. The two pitched covers produced no significant changes in microclimate or internal fruit quality compared with uncovered trees.

QUALITY OF FRUITS NATIVE TO LATIN AMERICA FOR PROCESSING: ARAZA (EUGENIA STIPITATA MCVAUGH)

Araza was domesticated in western Amazon, in the area that is now known as Peru. The fruit is very attractive to consumers for its delicious tart flavor, and is traditionally consumed as juice. The industrial processing of the juice could represent an attractive alternative to the traditional method of using frozen pulp, as it has a potential for longer storability. With the objective of evaluating the potential for processing, partially ripe (yellowish green) and ripe (yellow) fruits of araza were analyzed for physical, chemical and biochemical characteristics that could affect the process of juice extraction and stability, as well as the acceptability of the product. It was found that the pulp has a low soluble solids content (4.34oBrix) with very high titratable acidity (2.98%) as citric acid, and 0.64 and 1.45% total soluble sugars in green and ripe fruits respectively. The pulp yield is very high, between 85.86 and 88.57% according to maturity. The contents of starch (approximately 0.6%) in both stages and total pectin (between 0.34 and 0.39%) suggest that increase in yield with the use of processing aids such as enzymes could be of low significance. The native activity of pectic enzymes is relatively low, 4.33 EAU for poligalacturonase and 4,741.33 EAU for pectin methylesterase. The phenolic contents in all the extracted fractions can be considered low if compared to astringent fruits and no difference was found between stages of maturation. Ascorbic acid contents were respectively 31.78 and 33.70mg/100g.

Improvement of mishqui ( Solanum muricatum) earliness by selection and ethephon applications

The long period of time required for fruit ripening is a main drawback to the adoption of mishqui ( Solanum muricatum) as a new crop. Variation in the fruit ripening period was studied in 18 mishqui clones in response to ethephon sprays (0, 500 or 2000 mg l −1). Significant differences in the length of the fruit ripening period were detected between clones, ethephon doses and their interactions. Some clones did not respond to ethephon sprays, while in others the ripening period was shortened by more than 60%. In general, the effect of ethephon was greater in the clones with a longer ripening period. Furthermore, differences between clones of up to 20 days were found in the fruit growth period. Lengths of both periods (fruit growth and ripening) were not correlated, indicating that independent selection can be performed for both traits. The effects of ethephon on fruit quality characters were not significant in the majority of clones, although in five clones ethephon produced a skin degreening. Fruits from these clones had a higher firmness and lower soluble solid content (SSC) after ethephon treatment. On the other hand, ethephon sprays did not affect either the postharvest behaviour or the sensitivity to bruising. The results obtained here point to the existence of genotypic variation in the fruit ripening physiology of this species and they give relevant information for the improvement of mishqui earliness.

Yield, earliness and fruit quality of pepino clones and their hybrids in the autumn–winter cycle

The success of the pepino (Solanum muricatum Aiton) as a new crop for intensive horticultural areas relies on shortening the growing cycle and on securing a high standard of fruit quality. Irrigation with saline water and ethephon sprayings could be useful in achieving these goals. Two consecutive pepino crops consisting of two hybrids and their four parents were grown in the autumn–winter cycle. Plants were irrigated with water having electrical conductivities of 3 or 8 dS m−1 and full sized fruits were sprayed with ethephon at 0 or 500 mg l−1 . Salinity reduced yield and fruit size, although this effect was less important in the hybrids, which showed heterosis for yield characters. Overall, yields and fruit size of hybrids irrigated with saline water were greater than in the parents irrigated with non-saline water. Ethephon had no effect on yield characters. Salinity and ethephon improved earliness. In most clones combination of salinity and ethephon shortened the growing cycle by 1 month. Salinity improved fruit quality as it increased the soluble solids content (SSC) and dry matter (DM) in all clones, and titratable acidity (TA) in some cases. Ethephon sprayings had no marked effects on quality characters, except for parental clone 9-1 in which ethephon treated fruits had a lower SSC and TA. Organoleptic tests conducted on the best flavoured clones (0-8 and 6-10) showed that salinity improved fruit aroma and flavour although not texture, while ethephon had no effects. Results show that irrigation with saline water and ethephon sprayings improve earliness and fruit quality without dramatic yield depressions, especially in the hybrid clones. © 1999 Society of Chemical Industry

Mulch Types Affect Fruit Quality and Composition of Two Strawberry Genotypes

The influence of mulch types (black polyethylene, red polyethylene, and straw-vetch in raised bed hill culture) on the chemical composition of `Northeaster' and `Primetime' strawberry (Fragaria ×ananassa Duch.) fruit and plant parts was evaluated. Ascorbic acid (AA), malic acid, citric acid, and ellagic acid levels were higher in `Primetime' than in `Northeaster' fruits, while `Northeaster' had a higher soluble solids content (SSC). Fruit grown on straw-vetch had lower SSC than did those grown on the polyethylene mulches. The AA content in the fruit of either cultivar was not affected by the mulch treatment. Fruit grown on the straw-vetch mulch had less red surface and flesh color but higher pigment intensity than fruit grown on the polyethylene mulches. Strawberry plants grown on straw-vetch mulch had the largest leaf area and the highest chlorophyll content, while plants grown on red polyethylene mulch had the smallest leaf area and lowest chlorophyll content. There were significant mulch × cultivar interactions in fruit titratable acid (TA) and AA levels, sugars, citric and ellagic acid contents, leaf area and chlorophyll levels, and soluble carbohydrate and starch contents in leaves, petioles, crowns, crown-roots, and roots. TA was highest in `Northeaster' fruit when grown on red polyethylene, whereas TA was highest in `Primetime' fruit when grown on straw-vetch. The highest fruit citric acid levels were found in straw-vetch mulched plots of `Northeaster', and in black polyethylene mulched plots of `Primetime'. Ellagic acid accumulation was highest in `Northeaster' fruit grown on black polyethylene, and in `Primetime' fruit grown on red polyethylene or straw-vetch mulches. Fruit glucose content was highest in `Northeaster', but lowest in `Primetime', when grown on the straw-vetch mulch. There was a general tendency for soluble carbohydrate and starch levels in plant tissues to be lowest when the plants were grown in red polyethylene mulch and highest when grown in black polyethylene mulch. `Primetime' contained higher total carbohydrate levels than did `Northeaster' in all tissues tested.

Effects of soil applications of potassium sulphate on the mineral composition and eating quality of stored ‘Conference’ and ‘Doyenné du Comice’ pears

SummaryIn a ten-year trial, withholding K fertilizer to ‘Conference’ and ‘Doyenné du Comice’ trees did not cause leaf K to fall to deficient levels. Soil application of potassium sulphate raised leaf K by up to 0.4% above the optimum level, and fruit K concentrations were increased by up to 20 mg 100 g–1, and there was a slight yield increase in ‘Conference’ (but not ‘Cornice’) pears in the latter years. Potassium application influenced the uptake of other minerals into leaves and fruit, and in particular reduced their Ca and B status. Although the tendency for a lower starch content in fruit from fertilized plots suggested an advanced state of maturity, this was contradicted by the lower soluble solids content, and higher firmness of K-rich fruits at harvest. In taste-panel assessments on fruit ripened for 5 d at 18°C after storage at –1 to –0.5°C, no consistent differences between fruit from fertilized and unfertilized plots were detected in terms of flavour, sweetness, firmness or juiciness. Chemical analysis, however, showed that K application occasionally lowered fruit sugar concentrations, and consistently increased acidity. Improvements in eating quality are unlikely to be gained from increasing K application to trees already adequately supplied with this nutrient.

Variation in maturity traits within individual apples of cultivar Jonagold

SummaryVariation within individual apples of ‘Jonagold’ in firmness, soluble solids (sugar) content and starch conversion was strongly related to aspect. The south face of apples, relative to the north and east faces, had high firmness, low starch conversion and high soluble solids content. The Streif Index (a commonly-used composite measure of apple maturity) cancelled out the majority of the variation in the individual traits.

Volatile Emissions and Quality of Bagged `Fuji' Apples

Enclosing apple fruit in bags during development is widely practiced in Japan. Bags create a barrier that reduces damage from insects and fungal pathogens as well as treatments to control these problems. Bags also reduce the incidence of sunburn and change fruit appearance by altering peel pigmentation composition, two features that have prompted northwestern United States producers to bag `Fuji' apples. Fruit maturity and quality of bagged and nonbagged Fuji apples grown in Washington state were evaluated at harvest and after refrigerated storage in air or controlled atmosphere. Bagged fruit had less watercore and lower ethylene production at harvest compared to non-bagged fruit with similar starch ratings. Bagged fruit had lower soluble solids content, titratable acidity and firmness at harvest and during storage. Emission of ester and alcohol volatiles was consistently lower for bagged fruit. Postharvest volatile emissions were negatively correlated with bagging duration during development. Bagged fruit had no incidence of a peel disorder with similarity to delayed sunscald.

Differential Effects of Ethephon and Seniphos on Color Development of `Starking Delicious' Apple

The differential effects of two color improving products, ethephon an ethylene-releasing compound, and seniphos, a nonethylene-releasing product, were studied on `Starking Delicious' apples (Malus domestica Borkh L.). Ethephon and seniphos were applied 2 or 3 weeks before commercial harvest. Ethephon- and seniphos-treated fruit showed a significant improvement of peel color associated with a sharp increase in anthocyanin content and chromaticity values. Color improvement in ethephon-treated apples occurred during the preharvest period and cold storage. The seniphos-treated fruit stopped color development in cold conditions. In comparison to the ethephon-treated fruit, the seniphos-treated apples showed lower internal ethylene concentrations and a ripening delay. Both treatments sharply increased the activity of phenylalanine-ammonia-lyase enzyme, which seemed to be the determining factor of color enhancement. The seniphos-treated apples compared to ethephon had higher fruit firmness and lower soluble solids concentrations. Anthocyanin biosynthesis may be enhanced by seniphos treatment without inducing ethylene production or other ripening associated changes. As a consequence, fruit treated with seniphos can be held longer in storage.

Translucent Flesh Disorder of Mangosteen Fruit (Garcinia mangostana L.)

Characteristics of mangosteen fruit with normal and translucent flesh were determined. Fruit exhibiting translucent flesh disorder had significantly higher rind (65%) and flesh (82%) water content than fruit with normal flesh (63% and 80% in the rind and flesh, respectively). Specific gravity of translucent flesh fruit was >1 and that of normal flesh fruit was <1. Fruit specific gravity and natural transverse rind cracking were used to separate translucent-fleshed fruit from normal fruit. Translucent-fleshed fruit had a lower soluble solids concentration and titratable acid percentage than normal fruit. Translucent flesh was induced in normal fruit following water infiltration at 39 kPa for 5 minutes.

Coating Guavas with Cellulose- or Carnauba-based Emulsions Interferes with Postharvest Ripening

Harvested, mature-green guava (Psidium guajava L.) fruit were coated with cellulose- or carnauba-based emulsions to compare the effect on fruit ripening and quality of ripened fruit. Coatings containing 2% or 4% hydroxypropylcellulose significantly slowed softening an average of 35% or 45%, respectively, compared to uncoated fruit (a delay of 1 to 2 days in September and 4 to 5 days by January). A 5% carnauba formulation slowed softening by 10% to 30% and was most effective at reducing weight loss. Neither of the cellulose- nor the carnauba-based coatings affected the decay susceptibility of softened fruit, but coated fruit did not develop as much color, had a lower soluble solids concentration, and were more prone to surface blackening in storage than uncoated fruit.

Response in Green and White Asparagus to Supplemental Nitrogen and Harvest Date

`Jersey Giant' asparagus (Asparagus officinalis L.), grown in an Enders silt loam mineral soil, was given 80 kg supplemental N/ha either before or after the harvest season. Neither N application timing affected spear yield, objective color, or pigment concentration. Early supplemental N application decreased K concentration in white spears and Ca concentration in green spears. Green asparagus contained higher total-N, K, P, S, Ca, Mg, Fe, Zn, Al, Mn, and Cu concentrations but a lower soluble solids concentration (SSC) and NO3 than did white asparagus. As the cutting season progressed, spear SSC and S, Ca, NO3 (NO3 in white spears only), Zn, Mn, and Cu (Cu in white spears only) concentrations decreased, but spear K and Al (Al in white spears only) increased on a dry-weight basis. Fall residual soil NO3 levels were not affected by N application timing, but organic matter (percent) was lower in soil that received early supplemental N.

Tree Growth and Productivity and Postharvest Fruit Quality in Various Strains of `Delicious' Apple

Twenty-six strains of `Delicious' apple (Malus domestica Borkh.) were evaluated over several years for growth, yield, and fruit quality at harvest and after 6 months of storage. `August Red', `Rose Red', and `Sharp Red' had larger trunk cross-sectional area (TCSA) 3 and 18 years after planting compared to most other strains. `August Red' and `Starking' had larger TCSA and cumulative yield. `Apex,' `Improved Ryan Spur', `Silverspur', `Starkrimson', and `Wellspur' were also among strains with high cumulative yields and yield efficiencies. `Hardi-Brite Spur' and `Red King Oregon Spur' had moderately high yields and small TCSAs, thus, high yield efficiencies. `Atwood', `Hardispur', `Imperial', `Improved Ryanred', `Starkspur Supreme', and `Topred' had low cumulative yields. `Ace' and `Improved Ryanred' had low yield efficiencies. `Ace', `Imperial', `Red King Oregon Spur', `Rose Red', `Starking', and `Wellspur' had heavier fruit, while fruit weight in `August Red', `Hardispur', and `Starkrimson' was lighter than that in most other strains. `Redspur' and `Starkspur Supreme' had the largest length to diameter (L/D) ratios. `Early Red One' had a similar red skin color rating as `Rose Red.' The red skin color rating of `Early Red One' was significantly higher than that of all other strains. `Hi-Early', `Improved Ryanred', `Redspur', and `Starking' had the poorest skin color ratings. `Hardispur', `Nured Royal', `Silverspur', and `Starkrimson' had high soluble solids concentrations (SSCs) at harvest and after storage. `Early Red One', `Imperial', `Improved Ryan Spur', and `Red King Oregon Spur' had lower SSCs at harvest and after storage. Fruit of `Apex' and `Redspur' had relatively high firmness at harvest, while `Hardispur', `Silverspur', `Starkrimson', and `Starkspur Supreme' had firm fruit at harvest and after storage. `Hardi-Brite Spur' had the softest fruit after storage, and fruit from `Rose Red' had a lower firmness than most other strains at harvest and after storage. Considering cumulative yield, yield efficiency, or some quality parameters, `Apex', `Classic Red', `Improved Ryan Spur', `Red King Oregon Spur', `Silverspur', and `Wellspur' had satisfactory overall performance. Strains are also suggested for planting depending on the market situation and the demand for a particular quality factor. `Hardispur' and `Sturdeespur' (Miller) are not recommended for planting under climatic conditions similar to those of this experiment.

日本原産のカキ品種における果実成熟期, 果実重及び可溶性固形物含量の変異

One hundred and eighty-eight cultivars of oriental persimmon (Diospyros kaki Thunb.) native to Japan were evaluated for fruit ripening time (FRT), fruit weight (FW), and soluble solids content (SSC). A high heritability for each of these traits was conserved in this population; the overall mean and SD of FRT, FW and SSC were early to mid-November and 15 days, 200 g and 72 g, and 17.0% and 1.7%, respectively. Subgroups of PCA (pollination constant-astringent) and PVNA (pollination variant-nonastringent) showed wide variations for each trait. As to mean values, the PVNA group had slightly earlier FRT and higher SSC than the PCA group but their FW were similar. PCNA (pollination constant-nonastringent) group showed the latest FRT and the SSC was intermediate between those of PCA and PVNA groups; whereas, PVA (pollination variant-astringent) had the earliest FRT with the lowest SSC. The PCNA and PVA groups had larger fruits than the PCA and PVNA groups. Variations in FRT and SSC of PCNA were characteristically small, which suggest that these cultivars evolved later than the others.There is a weak, negative correlation between FW and SSC and a weak, positive one between FRT and FW. The percentage of early ripening cultivars was higher in cultivars which originated in the northern areas of Japan in contrast to those developed in southern regions.

Influence of light exposure on characteristics and storage life of kiwifruit

Abstract Quality and storage life of kiwifruit were investigated on fruits from shaded and exposed positions of the canopy and on fruits artificially shaded and grown in absence of light. At harvest the fruits grown in high light intensity have a high quality and can be stored for a long time; after 25 weeks of cool storage they have a soluble solids concentration > 14° Brix and a flesh firmness of c. 10 N. Fruits from shaded positions of the canopy showed significantly lower mean fresh weight and chlorophyll content (‐35%); at harvest and during storage they were slightly but consistently less firm and had lower soluble solids concentration than exposed fruits. Artificial shading of individual fruit for most of the growing season significantly reduced chlorophyll content in the mesocarp (‐77%), starch and alcohol‐soluble sugars concentration, flesh firmness, soluble content and dry matter, whereas the titratable acidity was significantly increased. The storage life of artificially shaded fruits was significantly reduced in comparison with exposed fruits, with significant increase in weight loss and fruit disease.

Accumulation of the Components of Total Solids in Ripening Fruits of Tomato

To identify qualitative and quantitative chemical variation in tomato fruit dry matter, crosses were made between the high soluble solids concentration (SSC) line LA 1501 (6.3% SSC when red-ripe) and the nearly isogenic commercial tomato cultivar VF 145B-7879 with a lower SSC (4.4% when red-ripe). Fruit samples from the parents and the reciprocal F1 hybrids were collected at 3-day intervals, from 25 to 52 days after anthesis, to evaluate the accumulation of various quality components throughout the development of the fruit from immature-green to red-ripe stage. Fructose and glucose concentrations, titratable acidity, pH, and percent dry weight (pulp and serum) were determined for each sample on a fresh basis. Fruit maturity was evaluated by puree color using Hunter `a' colorimeter values. Changes in most of the chemical constituents of the fruit were found to regress linearly with changes in fruit color. Regression of puree color against fruit SSC, and fructose, glucose, and total sugar concentrations described more of the observed variability in these components than days after anthesis, indicating that Hunter `a' colorimetric values provide a more precise measurement of fruit physiological age. The variation between the parents in fruit dry matter was found to be primarily due to differences in SSC. The ratio of fruit soluble to total solids concentration increased 23.7% in LA 1501 (from 61.6% to 85.3%) throughout ripening compared to-an increase of only 8.9% (from 66.3% to 75.2%) in `VF 145B-7879'. At the red ripe stage, LA 1501 possessed a 44% higher SSC than `VF 145B-7879'. Differences in fructose and glucose accounted for 41% of the variation in SSC between the two lines. An unidentified component(s) was responsible for the residual variation. Application of the genetic and physiological information generated from this study can be used to isolate and select for genes controlling accumulation of tomato fruit dry matter.

Thinning Pattern and Light Environment in Peach Tree Canopies Influence Fruit Quality

The effects of shoot length, fruit density, thinning patterns, and light levels on crop quality of peach (Prunus persica Batsch.) were investigated. On shoots 50 and 75 cm long, fruits were thinned to produce several distribution patterns, with peaches concentrated in the bottom, middle, or distal portion of the shoot, or uniformly spaced along the shoot at two fruit densities (≈10 or 15 cm between fruit). The lower fruit density on the longer shoots resulted in larger fruits. At the same fruit density, fruits clustered in the distal section of the shoot were smaller, with lower soluble solids concentration (SSC) and a smaller percentage of the exocarp colored red than for the other spacing patterns. Photosynthetically active radiation (PAR) was negatively correlated with the percentage of green exocarp and positively correlated with the percentage of red exocarp. However, the low correlation coefficients (0.45 and 0.50, respectively) indicate that even low light levels can result in substantial red pigment development in peach fruit.