), and beta-carotene content than fruits from plants without receiving any foliar K application ( Lester, 2005 ). In tomato, it has been reported that acid and reducing sugar contents, often correlated with K application, influence not only sweet and
Sofia Caretto, Angelo Parente, Francesco Serio, and Pietro Santamaria
Leah C. McCann and Philipp W. Simon
When stored at temperatures less than 10 °C, tubers of all cultivated potatoes exhibit cold-induced sweetening (CIS) during which starch degrades to sucrose, glucose, and fructose. Upon frying at high temperatures, the reducing sugars (Fru, Glu) interact with free amino acids via the non-enzymatic Maillard reaction to form dark-colored chips that are unacceptable to consumers. In addition, scientists recently discovered that the toxic chemical acrylamide is also produced during frying. Although storage at warmer temperatures reverses CIS and circumvents dark chip production, the probability of storage loss due to shrinkage and disease increases. Wild Solanum species form the backbone of many potato-breeding programs. In this study, we evaluated 36 different plant introductions (PI) including 20 different species, grown in Madison and Rhinelander, Wis., to identify germplasm resistant to CIS for genetic analysis. After storage for 2–3 months at 4 °C, tuber sugar and amino acid content were analyzed via HPLC and slices were fried to determine chip color. Sugar and chipping data support previous research indicating CIS resistance in S. okadae, S. raphanifolium, and S. phujera. Interestingly, some germplasm selections with high reducing sugar content produced light-colored chips, indicating exceptions to the typical correlation between reducing sugar content and chip color. Genetic bases to these exceptions are under evaluation.
Jorge Siller-Cepeda, Manuel Baez-Sañudo, Rosalba Contreras-Martinez, Laura Contreras-Angulo, Rosabel Velez, and Dolores Muy-Rangel
Banana fruits `Cavendish' type were obtained from a warehouse at color green stage. At arrival, fruits were taken out of boxes, dipped into a thiabendazole solution for 5 minutes, dried at room temperature and separated into three lots. One lot was sprayed with Fresh Seal™ (FS) at 3 °Brix, a second lot was treated with Semper Fresh™ (SF) at 1.2%, and the third was left as a control. After that, all fruits were packed again inside the plastic bags within the original carton boxes. Film-coated and control fruits were ethylene treated for 24 hours at 150 ppm, and vented for 24 hours until they reached color 3 (more green than yellow). After that, film-coated and control fruit boxes were collected inside 238-L airtight containers to apply Smartfresh™ (SMF) treatments at 0 and 300 ppb for 12 hours at 22 °C, complementing six different treatments. Later, fruits were stored at 22 °C and 80% to 90% relative humidity for 5 days to follow up changes. Quality evaluations were registered every day, including weight loss, firmness, color, CO2, ethylene, pH, titratable acidity, °Brix, and sugar spots. SF alone and the combinations SF + SMF and FS + SMF reduced weight loss as compared with the other treatments. SMF alone or in combination with FS or SF maintained higher firmness and delayed yellow color development as compared with the other treatments. Combinations of SF or FS with SMF delayed and reduced the incidence of sugar spots as compared with control fruits. Chemical characteristics were not significantly affected by the treatments, but SF + SMF had higher acidity and a lower pH. All treatments reached between 20 and 21 °Brix after 5 days. The data show that combined treatments of SMF and film coatings reduce sugar spot incidence, improving appearance and extending yellow life of fruits.
Rosilene Barbosa de Franca, Gerson Renan de Luces Fortes, and Adriano Nunes Nesi
The aim of this work was to evaluate the effect of sucrose on the in vitro muliplication of potato, cultivars Baronesa, Macaca, and Cristal. The nutrient medium used was the MS basal salts and vitamins added to 100 mg·L-1 myo-inositol. Four sucrose concentrations (20, 30, 40, and 50 g·L-1) were tested. The pH was adjusted to 5.9 before autoclaving. Each treatment had 15 explants, which were collected from the lower part of the shoot containing two buds. This material was inoculated in a 250-mL flask with 40 mL of nutrient medium. After inoculation the flasks were kept in a growth room under 25 ± 2 °C, 16-h photoperiod, and 19 μMol·m-2·s-1 radiation provided by cool-white fluorescent lamps for 30 days. This trial was designed in a randomized block with three replicates. Every 7 days, the parameters were collected as follows: number of buds, shoot length and number of shoots. It was observed that `Baronesa' presented the highest number of buds and rate of multiplication. `Cristal' had a slightly better performance for these parameters. Plants treated with sucrose at 50 g·L-1 led to a higher number of shoots. However, `Macaca' treated with sucrose at 40 g·L-1 had the highest shoot length.
Jesse Wimer, Debra Inglis, and Carol Miles
values; however, at Eltopia (where the V. dahliae soil density was relatively moderate), grafting ‘Sugar Baby’ onto ‘Rampart’ and ‘Tetsukabuto’ reduced AUDPC values. At Mount Vernon (where the V. dahliae soil density was relatively high), all grafted
Xun Li, Wenying Chu, Jinlong Dong, and Zengqiang Duan
chromogenic or fluorescent agents like tetrazolium blue ( D'Amboise et al., 1980 ) and benzamidine ( Kai et al., 1985 ) have weak responses to non-reducing sugars, which are abundant in root exudates. So, in many previous studies, only the reducing sugars in
Yong Zhang, Chunxia Fu, Yujing Yan, Xiaodan Fan, Yan’an Wang, and Ming Li
absorption spectrophotometer (Pye, Cambridge, U.K.). Determination of reducing sugar content. The samples was taken from the freezer and homogenized in 5 mL distilled water and centrifuged at 12,000 × g for 20 min. The precipitate was resuspended in
W.G. van Doorn
1 Senior scientist; e-mail: firstname.lastname@example.org . The concentrations of reducing sugars and polysaccharides in the mucilage fractions were determined by Yuan Zhong, and the sucrose concentrations by Erik Schaap. The cost of publishing this
Sandra M. Bijelić, Branislava R. Gološin, Jelena I. Ninić Todorović, Slobodan B. Cerović, and Boris M. Popović
characteristics. After stone extraction, the mesocarp underwent chemical analyses for TSC, SSC, total acids, total and reducing sugars, and contents of sucrose, vitamin C, Ca-pectates, proteins, cellulose, anthocyanins, and tannins. The analyses were performed by
Hui-juan Zhou, Zheng-wen Ye, Ming-shen Su, Ji-hong Du, and Xiong-wei Li
measurements and 6-d intervals for the three later measurements, and for simultaneous determination of fruit firmness, TSS content, TA, weight loss, and decay rate. The tissue used for determining TA and reducing sugar was stored at –80 °C in an ultra