Sun-drying Process Research Articles

Determination of Quality Characteristics of Holothuria tubulosa, (Gmelin, 1788) in Turkish Sea (Aegean Region) Depending on Sun Drying Process Step Used in Turkey

ABSTRACT There are around 500 species of sea cucumber but few (around 10-17) are valuable commercially. In Turkey, an Aegean region species, Holothuria tubulosa, is collected by divers and kept alive until processed. Generally, Chinese methods and processing techniques of sea cucumbers are applied in Turkey. Processing steps in Turkey consist of cleaning, gutting, boiling, cooling, sun drying, packaging and storage. In this study, quality characteristics of Holothuria tubulosa were determined depending on a sun drying process step used in Turkey: water activity (aw) and microbial quality of the sea cucumber were determined during sun drying period at different air conditions (temperature, wind velocity, humidity). Proximate analysis (crude protein, crude fat, moisture, carbohydrate) and chemical quality control analyses (total volatile base-nitrogen, trimetylamine-nitrogen, and thiobarbituric acid reactive substances) were also determined before and after sun drying of Holothuria tubulosa. According to the results of analysis, no quality criteria reached the maximum acceptability limit for the product.

Structural features of pectins from fresh and sun-dried Japanese persimmon fruit

Softening-associated changes in a cold-water-soluble pectin, CWP3 of Japanese persimmon fruit are investigated by methylation analysis. Methylation analysis showed that rhamnose occurred as (1 → 2)- and (1 → 2,4)-linked residues in CWP3 (from fresh persimmon), newly solubilized CWP3 (fraction ‘a’ from sun-dried persimmon) and depolymerized CWP3 (fraction ‘b’ from sun-dried persimmon) as expected for the presence of ‘hairy’ regions. Solubilization of pectin into CWP3 occurred with higher proportions of (1 → 5)-linked arabinan side-chains and lower proportions of (1 → 3)/(1 → 6)-linked arabinogalactan side-chains compared to the respective side chains in CWP3 (fresh persimmon). During the sun-drying process, marked losses of (1 → 3,6)-linked galactose residues from CWP3 occurred, due to extensive degradation of main-chains of arabinogalactans. This implied losses of both types of sugars, arabinose (as terminal) and galactose from arabinogalactans in CWP3 of Japanese persimmon. During the sun-drying process, the molecular size distribution of CWP3 was affected due to degradation of arabinogalactan and arabinan side-chains.

Modification of pectin in Japanese persimmon fruit during the sun-drying process

Cold-water-soluble pectic polysaccharides (CWPs) from fresh and sun-dried Japanese persimmon ( Diospyros kaki) were fractionated through DEAE-cellulose (phosphate form) column and in both cases, CWPs were separated into five fractions, CWP1, CWP2, CWP3, CWP4 and CWP5. Each CWP3 was subjected to gel filtration chromatography on a Sepharose CL-6B column. Gel filtration showed that solubilization of pectin as high-molecular-weight polymer into CWP3 and depolymerization of CWP3 occurred during the sun-drying process. CWP3 (fresh persimmon) contained galactose as the predominant neutral sugar, whereas arabinose was the predominant neutral sugar in newly solubilized CWP3. A low-molecular-weight fraction of CWP3 (sun-dried persimmon) represented mainly the rhamnogalacturonan backbone of ‘hairy’ regions. The molecular size distribution of CWP3 was affected due to degradation of side-chains. Loss of arabinose occurred at a slower rate than galactose from CWP3. The results imply a softening-associated modification of Japanese persimmon pectin during the sun-drying process.

Fate of quinoxyfen residues in grapes, wine, and their processing products.

Quinoxyfen is a new fungicide that belongs to the family of the quinolines, recently introduced to control powdery mildew (Uncinula necator). In this paper the fate of quinoxyfen residues from vine to wine and in their processing products was studied. After the last of four applications at the recommended rate, 0.38 mg/kg of residue was found on the grapes, which is under the legal limit fixed in Italy (0.5 mg/kg). The degradation rate was according to a pseudo-first-order kinetics (r = 0.964) and the half-life was 7.24 days. Vinification was carried out with and without maceration. During the vinifications without maceration <50% of the residues passed from the grapes to the musts. Separation of the lees (8%) from the must by centrifugation caused no detectable residues in centrifuged must. At the end of fermentation with and without maceration no quinoxyfen residues were determinable in the wine. No effect on the alcoholic or malolactic fermentation was observed even in the presence of higher quinoxyfen concentrations than those found in the grapes at harvest time. During fermentation, the yeasts partially degraded the pesticides and completly adsorbed them. Bacteria, on the other hand, do not have any degradative effect on the pesticides. The raisins obtained by sun-drying did not contain any residues, whereas those obtained by oven-drying show the same amount of residues as in the fresh grapes. During the sun-drying process the fruit weight decreased by a factor of 4; the decrease in the oven-drying was equivalent. Samples of dregs and liquid lees, fortified with high levels of quinoxyfen. were double-distilled. The first dregs distillate, with an alcohol content of 32.1%, did not show any residues, whereas the first lees distillate, with an alcohol content of 34.5%, showed 7% of the initial residues. After the second lees distillation, the obtained product showed an alcoholic content of 81.2% and no residues of quinoxyfen (<0.01 mg/kg).

A study of the role of tissue disruption in the removal of cyanogens during cassava root processing

Sun-drying as a means to reduce the cyanogen content of cassava roots is commonly known to be inefficient. This paper reports on modifications to the processing procedure used for sun-drying and their effectiveness at removing potentially toxic cyanogenic glucosides. Commonly used processing methods were compared. Crushing cassava root pieces prior to drying was found to significantly improve the efficiency of cyanogen removal by, on average, 22% during laboratory experiments and 12% during field trials. The crushing procedure was optimized and a low cost prototype crusher developed. A reduction in the processing time resulted from crushing the root disks prior to drying. The processing method involving crushing was ranked second in terms of efficiency of cyanogen removal in a comparative study of sun-dry processing methods that are commonly used in East Africa. Pounding cassava to small pieces in a traditional pestle and mortar prior to drying was the most efficient, providing 90% removal of cyanogens. Pounding and crushing cassava prior to sun-drying were significantly better than all other root preparation pre-treatments evaluated.

Storage of Cassava Chips (Manihot esculenta): Insect Infestation and Damage

SUMMARYInsects cause serious problems during the storage of cassava chips, when quality may be reduced and significant quantities of the product consumed. The major species naturally infesting chips were Rhizopertha dominica, Lasioderma serricorne and Araecerus fasciculatus. Infestation occurs during the sun-drying process, and up to 16% reduction in chip weight due to insect feeding was recorded after 2 months storage. Chips that had not received any pre-drying storage, but contained salt as a preservative, were infested by fewer insects than chips without salt. The poorest quality chips had significantly more insects than better quality ones.

Biochemical Analysis Of Some Dried Sis Fishes Of The River Padma In Rajshahi

Seven different species viz. Chanda baculis, Chanda ranga, Amblypharyngodon mola, Oxygaster bacaila, Clupisoma atherinoides, Corica soborna, Mystus vittatus and a group of mixed SIS fishes viz. Mastacembelus pancalus, Xenntodon cancila, Chanda baculis and Glossogobius giuris were used for preparation of dust which can be preserved for a time period. The fishes were sun dried or oven dried, which are also method of preservation. Quality of the oven-dried fish was better than that of the sun-dried fish, but sun-drying process is easy and can be used in large scale. The fish powder remained in good condition for 7-9 months at normal room temperature, but at -18°C the powder was in good condition throughout the year. Highest quantity of powder from 1 kg of fish was obtained in case of the mixed species as 24.61% and the lowest in O. bacaila which was 20.52%. Biochemical analysis showed that the maximum calcium content was found as 1.34% in M. vittatus and minimum was 0.80% in mixed SIS fishes. Maximum phosphorus content was 2.90% in C. ranga and minimum was 1.72% in C. soborna. Maximum iron content was found as 45.20 mg/100g in mixed SIS fishes and minimum was found as 16.85 mg/100g in O. bacaila. The maximum moisture content was found in C. ranga (13.50%) and the minimum in mixed SIS fishes (11.65%). The maximum protein content was recorded in the mixed SIS fishes (72.45%) and the minimum in C. ranga (52.65%). The experiment was replicated three times and conducted from July 2005 to July 2008. DOI: http://dx.doi.org/10.3329/jles.v6i0.9719 JLES 2011 6: 39-43

Novos ensaios sôbre a seca das sementes de café ao sol

Compreendendo diversos ensaios realizados à sombra, ao sol e por meio de agentes químicos, o presente trabalho foi executado com o objetivo de eliminar dúvidas que existiam na literatura, especialmente quanto à possibilidade de se efetuar a seca da semente de café exclusivamente ao sol. Tendo em vista a confirmação integral dos resultados anteriormente publicados pelo A., pode-se afirmar que o processo de seca a pleno sol é perfeitamente viável para essa semente, desde que o seu teor de umidade não decresça, durante a seca, abaixo de 8-9%. Abaixo dêste ponto crítico a semente perde ràpidamente seu poder germinativo, mesmo quando desidratada por meio de agentes químicos, à temperatura ambiente.