Flesh Texture Research Articles

"Il avait retrouvé le secret de Pygmalion" : Girodet, Canova e l'illusione della vita

Chiara Savettieri, "Il avait retrouvé le secret de Pygmalion" : Girodet, Canova and the illusion of life ; This paper intends to highlight the relationship between the French painter Anne-Louis Girodet-Trioson and the Italian sculptor Antonio Canova. The works by Girodet in which one can distinguish connections with the sculptor are the Endymion and Pygmalion and Galatea. In the former, one can observe various similarities with the aesthetics of Canova : these are particularly recognizable in the staging of the light in order to reproduce the smooth texture of flesh and in a conception of beauty particular to Winckelmann, which, by its "indeterminate" nature, appears androgynous and ephebic. Following the wishes of its patron, that is to say Sommariva, the Pygmalion was to constitute a tribute to Canova who was able to breathe life and the illusion of movement to his marble statues. In this painting, it is possible to distinguish precisely both the similarity but also the contrast with the sculptor. On the one hand, Girodet, like Canova, believes that art is composed of a significant intellectual element, which bathes the works in a cool sheen, far removed from the fervent spontaneity of Canova's marble statues. However, if one looks closer, it appears that this intellectualism stems from a deep mise en abyme of the values on which the neoclassical aesthetics was based : a crisis that appears extremely clearly in the numerous texts written by the painter throughout his life.

PERFORMANCE OF BRAZILIAN STONEFRUIT VARIETIES IN A TEMPERATE REGION OF AUSTRALIA

Nineteen peach [Prunus persica (L.) Batsch] and two nectarine varieties from Brazil were evaluated at the Applethorpe Research Station, Stanthorpe, Queensland in 1996-1997. Within this group there was variation in flesh acidity, flesh colour (white and yellow) and flesh texture (melting and non-melting). The peach varieties BR-2, BR-4, BR-6, Diamante, Esmeralda, Jade, Magno and Safira were yellow fleshed, non-melting types with no red blush. Eldorado, a non-melting flesh peach, had a 25% blush but was considered unattractive for fresh market use. The peach varieties BR-1, BR-3, Chula, Coral, Escarlate, Pilcha and Premier were all subacid (Honey) types. Lotus, a small and unattractive nectarine, had a total soluble solids content of 24% and a flavour rating of 5 (most desirable).

Resolution of quantitative trait loci for mechanical measures accounting for genetic variation in fruit texture of apple (Malus pumila Mill.)

Different attributes of fruit flesh texture contribute to consumer preference for eating quality in apple. We extended previous studies in order to determine whether a range of mechanical measures could resolve further the genetic contribution to variation in the physical attributes of apple fruit flesh. In particular we were interested in accounting for variation of the sensory traits crispness and juiciness. A quantitative genetic analysis of mechanical measures derived from compression and wedge fracture tests was carried out. This was based on segregation in an unselected mapping population which had previously been used to identify QTLs associated with penetrometer readings, stiffness by acoustic resonance, and a range of sensory descriptors. For wedge fracture tests significant QTLs were detected on L16 and L01. Those on L16 corresponded with positions previously determined for sensory measures of crispness and juiciness. Distance at maximum force was accounted for by a single QTL on L16 and correlated well with crispness and juiciness, suggesting that it may be appropriate for the selection of genotypes with fruit posessing desirable texture attributes. We established that the association of the sensory texture QTL on L16 is unlikely to be due to perceptual interactions with the Ma acidity locus. For compression measures, QTLs were detected on L01, L06, L08 and L15. Specific gravity is well-correlated with compression stiffness modulus, and both have a significant QTL on L06. Measures of cell size and shape determined across the population failed to detect any significant QTLs.

Effect of Different Fertilizer Application Levels on Texture of 'Hakuho' Peach(Prunus persica Batsch).

Effects of different fertilizer application levels on the flesh texture of peach fruits were investigated. Four-year-old 'Hakuho' peach trees trained to a central leader system were supplied with complete liquid fertilizers comprising higher (160 ppm), medium (80 ppm), or lower (40 ppm) levels of N. The fertilizer levels were lowered to half for each at the stone hardening stage. The fruit harvested from the H treatment trees reached the shipping maturity stage 4 to 6 days later than the fruits from the L and M treatment trees. The flesh firmness of the H treatment fruit was significantly lower than those from the M and L treatment fruits when compared at the shipping maturity stage in each treatment. The flesh softening was apparently accompanied with increased ethylene emission from the fruit. The flesh of the H treatment fruits contained higher levels of water-soluble pectin and cellulose, and lower levels of HCl-soluble pectin and starch than those from the M and L treatment fruits at the pre-mature stage. In addition to that, a higher level of K and a lower level of Ca were analysed in the flesh of the H treatment fruit than the other treatments. These results indicate that the peach fruit grown under using a high amount of fertilizer application deteriorates the flesh texture at the time of harvest mainly because of the unbalanced mineral nutrition and delayed fruit ripening than the normally fertilized fruits.

Cell Wall Enzymes and Cell Wall Changes in `Flavortop' Nectarines: mRNA Abundance, Enzyme Activity, and Changes in Pectic and Neutral Polymers during Ripening and in Woolly Fruit

Most `Flavortop' nectarines [Prunus persica (L.) Batsch (Nectarine Group)] that were placed directly into 0 °C storage developed chilling injury after removal, while preconditioning fruit for 2 days at 20 °C (delayed storage) reduced chilling injury substantially. Chilling injury was expressed as the development of a dry, woolly flesh texture during ripening. Delayed-storage fruit were as firm as control fruit when placed in storage, but softened more during storage. Analysis of cell wall components showed that in woolly fruit a higher percentage of pectin was retained in the sodium carbonate fraction, although during ripening polymers in this fraction decreased in molecular mass (Mr). In the guanidine thiocyanate hemicellulose fraction of woolly fruit, the associated pectin and hemicellulose remained as large polymers, while in delayed-storage fruit they decreased in Mr during ripening. Endo-polygalacturonase (PG), pectin esterase (PE), and endo-glucanase (EGase) activities of delayed-storage fruit were the same as control fruit at the beginning of storage, although exo-PG was higher. However, differences were observed at the end of storage. Endo-PG activity was lower in control than delayed-storage fruit at the end of storage while PE activity was higher, and exo-PG and EGase activities were similar. These differences in activity were not reflected in the mRNA abundance of the respective enzymes. Endo-PG and PE message was similar in all fruit at the end of storage and increased during ripening, while EGase message was low at all times except in control fruit after storage and development of woolliness. Prevention of chilling injury by delayed storage appears to be due to the ability of the fruit to continue a progressive, slow cell wall degradation in storage which allows normal ripening to proceed when the fruit are rewarmed. Regulation of the softening process did not appear to be by enzyme synthesis, since mRNA levels of the enzymes did not correspond with enzyme activity.

PINEAPPLE BREEDING AT CIRAD. II. EVALUATION OF ‘SCARLETT’, A NEW HYBRID FOR THE FRESH FRUIT MARKET, AS COMPARED TO ‘SMOOTH CAYENNE’

'Scarlett', a clone selected from a 'Smooth Cayenne' x 'Manzana' progeny was tested against 'Smooth Cayenne' in Martinique, following an experimental design composed of 50-plant plots, with four replications organised in bivarietal blocks, and repeated six times at a two-month interval. Planting material consisted of 300-350 g suckers, produced from 3,000 vitroplants of each cultivar. 'Scarlett' shows less vegetative development than 'Smooth Cayenne', as expressed in D leaf weight and suckering. The plant is more compact and erect, with completely smooth leaves. Fruits are smaller, which is partially compensated by a better response to floral induction, a much shorter production cycle and more uniformity in fruit weight. The crown is lighter but long and erect. Although peduncle is longer in 'Scarlett', lodging is less frequent than in 'Smooth Cayenne'. Fruit quality is much better, externally as well as internally, with a uniformly bright orange to red colour, a regular and cylindrical shape, flat and relatively large eyes, a uniform golden yellow firm flesh. Core is thinner and flesh texture is less fibrous and crispier. It is sweet and savoury, with a sugar content above that of 'Smooth Cayenne', and comparable acidity values. Ascorbic acid content is higher, The internal gradient of maturity is much less marked than in 'Smooth Cayenne'. Unfortunately, 'Scarlett' seems more susceptible to Penicilliumfuniculosum attacks. A proliferation of slips was observed, which seems to bc an effect of the preliminary in vitro multiplication phase. (Resume d'auteur)

Effects of altered ration levels on sensory characteristics, lipid content and fatty acid composition of rainbow trout ( Oncorhynchus mykiss)

This study describes the effects of altered ration levels on sensory characteristics, lipid content and fatty acid composition of rainbow trout fillet. Ration levels were altered from adequate to restricted level after 0.2 and 1.0 years from hatching and from strongly restricted and restricted levels to adequate level 1.0 years from hatching. A selected and trained panel carried out descriptive sensory tests on fish fillet cross-sections. The intensity of total odour increased, and that of juiciness decreased with age, independent of ration level. Ration level had an overall effect on the total taste intensity, independent of age. Fresh odour correlated negatively to the saturated fatty acids 14:0 ( r=−0.834; p<0.001), 16:0 ( r=−0.831; p<0.001) and 18:0 ( r=−0.668; p<0.05). Trout that had their ration level altered from restricted to adequate level 1.0 years after hatching had a higher lipid content than trout having their ration level altered from adequate to restricted level after 0.2 and 1.0 years, respectively. Including fillet lipid content in the statistical model indicated that lipid is an important factor decisive for total taste and flesh texture of the trout. Fish having their ration level altered from adequate to restricted level after 0.2 years had a significantly lower condition factor than fish having it altered 1.0 years after hatching.

A RESEARCH NOTE: EFFECT OF SUGAR TYPES AND CITRIC ACID CONTENT ON THE QUALITY OF CANNED LYCHEE

ABSTRACTThe effects of sugar and citric acid content on the color and texture of canned lychee were investigated. For two major cultivar of lychee grown in Taiwan, Hau‐yen and No‐mitzu, with 0.2% citric acid added to the syrup, the pink discoloration could be reduced and a better texture of lychee flesh maintained if the sugarcontent in the syrup was adjusted nearly to that of the fruit flesh. Among the sugar types tested, sugar mixtures which had the same ratio of sugar types in the syrup as in lychee flesh provided better quality in canned lychee flesh than sucrose alone.

060 `Blake's Pride' Fire Blight-resistant Pear Cultivar

`Blake's Pride' has been released jointly by USDA and The Ohio State Univ. as a new fire blight-resistant cultivar. The original seedling tree was selected in 1977 at the Ohio Agricultural Research and Development Center in Wooster by R.C. Blake and T. van der Zwet from a cross of US 446 × US 505, performed in 1965 by H.J. Brooks, and was tested under the original seedling number, OHUS 66131-021. The fruit of `Blake's Pride' is pyriform to round-pyriform in shape, and is moderate in size, averaging ≈2.75″ to 3″ in diameter, and 3.25″ in height. The stem is short, medium in thickness, and upright. Skin undercolor is yellow, the finish is glossy, and 20% to 30% of the fruit surface is covered with a smooth, light tan russet. Harvest maturity occurs about 3 weeks after `Bartlett', and the fruit will store in air storage for at least 3 months without core breakdown or superficial scald. The flesh texture is moderately fine, juicy, and buttery. Grit cells are moderately small and occur primarily around the core and in a thin layer under the skin, similar to `Bartlett'. The flavor is subacid and aromatic. The tree is moderate in vigor on `Bartlett' seedling rootstock, and upright-spreading in habit. Yield has been moderate to moderately high. Fire blight infections are rare, and extend no further than 1-year-old growth. Artificial blossom inoculations indicate a moderate degree of resistance of blossoms to fire blight infection. Resistance of `Blake's Pride' to both shoot and blossom infection is much greater than that of `Bartlett'.

Soft-rot resistance combined with other tuber characters in long day-adaptedSolanum phureja

Offspring were produced from a cross between two long-day-adaptedSolanum phureja clones which carried resistance to tuber soft rot (Erwinia carotovora subsp.atroseptica). In tests carried out on the produce of field-grown plants raised from tubers, over fifty per cent of the 173 offspring were found to be highly resistant. Assessments were also carried out of tuber yield, mean tuber weight, tuber number, shape, regularity, flesh colour, texture of the steamed flesh, fry colour, after-cooking blackening, sprout length after storage and overall dormancy. There were statistically significant differences between clones for all characters (P<0.001).

Pathology and morphology of Ichthyophonus hoferi in naturally infected fishes off the Swedish west coast.

The pathology and morphology of Ichthyophonus hoferi was studied in naturally infected Atlantic herring Clupea harengus, in sprat Sprattus sprattus, and in flounder Pleuronectes flesus from the west coast of Sweden. The pathogen was found in all organs examined, with the intensity of infection varying in different organs of the different fish species. Two main phases in the life of infecting parasites were identified, 'active' and 'passive', the latter being able to switch to active. The active phase of the infection in herring was usually accompanied by a lean and slender appearance of the body, a drastic decrease in intestinal fat, emaciation of the somatic muscles, swelling of the visceral organs, poor quality of flesh texture and a distinctive off-odour. The most characteristic macroscopic sign of ichthyophonosis in herring and flounder was the occurrence of creamy white nodules on the heart. The infection causes a chronic systemic granulomatous inflammation. The nature of the granulomatous inflammation was host- and tissue-dependent. The pathogenicity of the parasite in its active form and the side effects of host defence cells were also reflected in dramatic tissue damage and loss of structure and function of the infected organs. Three kinds of spores were identified: 'un-developing spore', 'developing spore' and 'plasmodio-spore'. The formation and spread of 'plasmodia', from plasmodio-spores, as a secondary infection agent is documented. Transmission electron microscopy revealed I. hoferi to be multinucleated, containing different organelles and structures. These included a cell wall, an undulating cell membrane, a thin paramural endoplasm, an endoplasmic reticulum, polymorphic but usually spherical mitochondria with short tubulo-vesicular cristae, dictyosomes with plate-like cristernae, large electron-dense lipid droplets and electron-lucid vacuoles, probably containing glycogen.

Taxonomy of Kudoa species (Myxosporea), using a small-subunit ribosomal DNA sequence

Myxosporeans in the genus Kudoa infect the flesh of many marine fishes and often cause unsightly lesions and softening of the flesh texture. We are particularly interested in K. thyrsites because it is associated with soft flesh in the Atlantic salmon (Salmo solar), an important commercial species in Canada. Sequences of the small-subunit (SSU) rDNA (about 1600 base pairs) were obtained from K. miniauriculata, K. amanuensis, and K. poniformis. We aligned these sequences with one obtained from coho salmon (Oncorhynchus kisutch) and designed "Kudoa general" primers (KUD1f and KUD2r). These primers, in combination with other general primers, were then used to obtain the SSU rDNA sequence of K. thyrsites from two host species, Atlantic salmon and tubesnout (Aulorhynchus flavidus), from British Columbia, Canada. Sequence comparisons of these isolates indicated that Kudoa species cluster by geographic location rather than by morphology of spores. The three species from the eastern Pacific were approximately 97% identical, whereas K. amamiensis (from Japan) was about 91% identical with these species. Sequence comparisons of K. thyrsites from Atlantic salmon and tubesnout revealed a difference of only 0.07% between these isolates. Comparison of SSU rDNA sequences from the four Kudoa species and Henneguya salminicolo analyzed in this study with those from other available myxosporean genera (Myxidium and Myxoholus) showed that taxonomic divisions at the order and suborder levels were consistent with classical views of the taxonomy of the Myxosporea. Using specific regions of the SSU rDNA, we also developed a sensitive and specific polymerase chain reaction test for detection of K. thyrsites.

A New Source of Peach Germplasm Containing Semi-freestone Nonmelting Flesh Types

A freestone, nonmelting flesh peach would offer the opportunity to transport freestone peaches to distant markets, and so open lucrative export opportunities. Peach [Prunus persica (L.) Batsch.] germplasm segregating for semi-freestone and clingstone has been identified among the nonmelting flesh, open-pollinated progeny of the Univ. of Florida selection, Fla. 9-20C. The segregation approached a 1 : 1 ratio. No significant differences were detected between the two categories for titratable acidity, soluble solids concentration, or skin color. However, the semi-freestone progeny had significantly softer flesh than their clingstone siblings, although not soft enough to justify reclassification of the flesh texture. No simple genetic model can be proposed for the inheritance of this new phenotype. The semi-freestone, nonmelting germplasm represents a step towards a less perishable, freestone cultivar for the fresh market, as well as an opportunity to study the reason for the rarity of the freestone/nonmelting phenotype among peaches.

Changes in Hemicellulose-associated Pectin during Softening of Peach Fruit

Softening to a normal melting flesh texture in peaches involves a combined participation between polymers located in the middle lamella and primary cell wall. Pectins located in the primary cell wall polysaccharide matrix which cosolubilize when hemicellulose is extracted with KOH have received less attention than the chelator or sodium carbonate soluble pectin likely to be associated with the middle lamella. We conducted a series of extractions for cell walls prepared from softening peach fruit (47, 30, and 15 N firmness) using 0.5 m imidazole, sodium carbonate and a graded series of KOH. Hemicellulose-associated pectin was a substantial proportion of most KOH extracts (30 to 50 mole percent) and fractionated on size exclusion chromatography as a high apparent molecular weight peak which became more prominent as fruit softened and could be separated from two lower apparent molecular weight peaks by anion exchange chromatography. The nature of a hemicellulose-pectin interaction in peach was apparently by physical entrapment, versus covalent cross-linking. Softening related changes in hemicellulose-associated pectin will be addressed.

Relationship between Texture and Cell Wall Polysaccharides of Fruit Flesh in Various Species of Citrus

Various species and cultivars of citrus were studied to determine the relationship between texture and cell wall polysaccharide content of fruit flesh. Among those tested cultivars, navel orange (Citrus sinensis Osbeck) and hassaku (C. hassaku Hort. ex Tanaka) were firmest, `Fukuhara orange' (C. sinensis Osbeck) was intermediate, and satsuma mandarin (C. unshiu Marc.) was softest. There was a 3-fold difference in firmness among the 12 citrus cultigens measured. Cohesiveness values ranged from 0.30 to 0.49 and were not correlated with fruit firmness. Sugar content in each cell wall fraction was highest in the water and EDTA fractions, followed by the hemicellulose fraction, and was lowest in the cellulose fraction. Correlation coefficients between firmness and sugar content ranged from 0.69 to 0.88 and were highest in the cellulose fraction. This study suggests that firmness of fruit flesh among the cultigens is influenced by cell wall polysaccharide composition. Chemical name used: ethylenediaminetetraacetic acid (EDTA).

Dietary influences on product quality in African catfish (Clarias gariepinus)

In this trial a full-sib family of Clarias gariepinus was raised under standard conditions in a warmwater recirculation system. The fish were divided into two experimental groups of 1200 individuals each and were raised in separate tanks. The groups were fed two experimental diets differing in crude protein (group I 40% and group II 52% DM) and crude fat (group I 8% and group II 13% DM). Gross energy was 21.3 and 22.1 MJ/kg. Slaughtering of 100 fish per group (50 males, 50 females) took place after two experimental periods. Besides the significant effect of the diets on body weight and size, a higher degree of corpulence was observed in group II. Tissue and organ percentages were not influenced, except a higher intestinal fat deposition in intensively fed fish. This group also showed a higher carcass weight. More expressed differences between both feeding alternatives were observed in physical and chemical flesh quality criteria. In group I texture of flesh was firm and water-binding-capacity was significantly increased in group II. The appearance of the filet was affected by the diet. Intensively fed catfish showed a tendency to a lighter and more yellowish colour. The chemical composition of the flesh indicated a significant increase of dry matter caused by higher protein and fat contents in this group. A strong influence of sex and fattening age on inner and outer product quality was evident. High fat and protein content of the diet has a certain influence on product quality in African catfish. It can be concluded that there is a clear effect of diet on quantitative criteria with a tendency to higher slaughtering yields in intensively fed catfish.

`Platonivs'ka': A New Scab-resistant and Cold-hardy Pear Cultivar

`Platonivs'ka' has been released as a new autumn pear cultivar that combines scab (Venturia pirina Aderh.) resistance and cold hardiness under Ukrainian climate and soil conditions, selected from a cross of `Hybrid 1931' (`Oleksandrivka' × `Dekanka du Comice') × Beurré Bosk. The trees grow vigorously, are adequately winter-hardy, and resistant to both leaf and fruit scab. Very good tree productivity has been observed when `Platonivs'ka was grafted on Limonska Oleksandrivka, Wild Forest Pear, Quince A, or BA-29 rootstocks. The fruit attains its picking ripeness between 10 and 20 Sept. (2 weeks after `Bartlett') and eating ripeness between the beginning and end of October in Ukraine. Its storage life at 0 to 2C lasts until the end of January. The average weight per fruit ranges between 180 and 200 g (70–75 mm in diameter). The fruit eating quality is excellent; its juicy and pleasant sugar/acid ratio makes it a very good dessert pear. Fruits are ovatepyriform in shape. Their skin color is light grayish-green and their finish is glossy at harvest. Flesh texture is moderately find and buttery. At harvest, grit cells are small and evenly distributed in the flesh and they become inconspicuous when the fruit is held at 20C for a week. `Platonivs'ka' is recommended for both home and commercial orchards.

Changes in physiology, composition and sensory characteristics of Australian papaya during ripening

Australian papaya fruit were held at 20, 25 and 30�C and physico-chemical and sensory changes occurring during ripening observed. Fruit at 20�C showed a respiratory climacteric after about 5 days at which time peel colour was 20-50% yellow. The peak in ethylene production occurred about 1 day after the climacteric. The major physico-chemical changes were increases in ascorbic acid and total carotene, and a decrease in benzyl isothiocyanate (BITC). Maximum sensory characteristics were attained 2 days after peel showed a full yellow colour. Fruit held at 25 and 30�C ripened faster, had higher concentrations of total carotene and ascorbic acid, firmer flesh texture, a lower BITC level, more intense yellow peel colour and more acceptable eating attributes. Australian papaya would therefore be more acceptable to consumers if ripened at elevated temperatures rather than at 20�C.

515 PB 447 `POTOMAC': A NEW FIRE BLIGHT-RESISTANT PEAR CULTIVAR

`Potomac' has been released as a new pear cultivar which combines a high level of resistance to fire blight with excellent fruit quality. Selected from a cross of `Moonglow' × `Beurre d'Anjou', it was tested under the seedling number, US 62537-048. Fruit are ovate-pyriform in shape, and average 73mm in diameter. Skin color is light green and the finish is glossy at harvest maturity, which occurs about 2 weeks after `Bartlett'. Flesh texture is moderately fine, buttery, and juicy; grit cells are small and limited to a thin layer under the skin. Flavor is subacid, with mild aroma, and similar in character to `Beurre d'Anjou'. Fruit may be ripened after harvest without cold storage, but `Potomac' is more susceptible to superficial scald than Beurre d'Anjou if stored for more than eight weeks. The tree is moderately vigorous. Yield and precocity are moderate. Fire blight resistance is greater than that of `Seckel', with a high degree of resistance in both shoots and blossoms. The cultivar is recommended for home orchards and limited commercial trial.

Culinary quality of tubers derived from Solanum phureja and S. tuberosum × S. phureja hybrids

SUMMARYClones from the potato species Solanum phureja and 2x and 4x hybrids between S. phureja and S. tuberosum were tested for the culinary quality of their tubers following steaming, frying and baking. The quality of S. phureja tubers was high but material from the F 1 hybrids showed more disintegration or blackening after cooking than either parental species. Tetraploids produced by backcrossing 4x Fl hybrids toS. tuberosum cultivars showed less of these defects.Fourteen S. phureja and 2x F1 hybrid clones selected for their unusual tuber skin pigmentation or shape were found to have a variety of baked flesh colours from orange-yellow to cream with red marbling. Their cooked flesh texture was generally floury and often crumbly. It is suggested that S. phureja material could be exploited as a novel food source for specialized use in North European countries.