Individual Shrink Wrapping of Zucchini Fruit Improves Postharvest Chilling Tolerance Associated with a Reduction in Ethylene Production and Oxidative Stress Metabolites

We have studied the effect of individual shrink wrapping (ISW) on the postharvest performance of refrigerated fruit from two zucchini cultivars that differ in their sensitivity to cold storage: Sinatra (more sensitive) and Natura (more tolerant). The fruit was individually shrink wrapped before storing at 4°C for 0, 7 and 14 days. Quality parameters, ethylene and CO2 productions, ethylene gene expression, and oxidative stress metabolites were assessed in shrink wrapped and non-wrapped fruit after conditioning the fruit for 6 hours at 20°C. ISW decreased significantly the postharvest deterioration of chilled zucchini in both cultivars. Weight loss was reduced to less than 1%, pitting symptoms were completely absent in ISW fruit at 7 days, and were less than 25% those of control fruits at 14 days of cold storage, and firmness loss was significantly reduced in the cultivar Sinatra. These enhancements in quality of ISW fruit were associated with a significant reduction in cold-induced ethylene production, in the respiration rate, and in the level of oxidative stress metabolites such as hydrogen peroxide and malonyldialdehyde (MDA). A detailed expression analysis of ethylene biosynthesis, perception and signaling genes demonstrated a downregulation of CpACS1 and CpACO1 genes in response to ISW, two genes that are upregulated by cold storage. However, the expression patterns of six other ethylene biosynthesis genes (CpACS2 to CpACS7) and five ethylene signal transduction pathway genes (CpCTR1, CpETR1, CpERS1, CpEIN3.1 and CpEN3.2), suggest that they do not play a major role in response to cold storage and ISW packaging. In conclusion, ISW zucchini packaging resulted in improved tolerance to chilling concomitantly with a reduction in oxidative stress, respiration rate and ethylene production, as well as in the expression of ethylene biosynthesis genes, but not of those involved in ethylene perception and sensitivity.This work was supported by grants AGL2011-30568-C02/ALI from the Spanish Ministry of Science and Innovation, and AGR1423 from the Consejería de Economía, Innovación y Ciencia, Junta de Andalucía, Spain. Z.M. acknowledges FPU program scholarships from MEC, Spain. S.M. is funded by grant PTA2011-479-I from the Spanish Ministry of Science and Innovation

Effects Of Chilling On Tomato Fruit Ripening

The alteration of fruit ripening is a common chilling injury (CI) symptom in tomato. To evaluate whether tomato can be used as a model study for an altered fruit ripening associated with CI, the effect of chilling on fruit ripening have been investigated in tomato fruit cv. Trust (Solanum lycopersicum L.cv Trust) and tomato introgression line 11-2 (IL 11-2). Tomato fruit were harvested at breaker stage of maturity and ripened at 20 oC for up to 14 d, or stored at 3 oC for up to 4 weeks, and then ripened at 20 degrees C. In Trust tomato, the effects of chilling on fruit ripening were small, and the mealiness disorder was not detected. Chilling had a marked effect on gene expression, total activity, and protein accumulation of PG. However, pectin solubilization and depolymerization did not seem to be affected much by chilling. The expression of LeEXP1 was reduced by chilling, but LeEXP1 protein accumulation level was not affected. Post-transcriptional regulation of PG and LeEXP1 affected by chilling was observed. In IL 11-2 tomato, the effects of chilling on fruit ripening and the expression of ripening-related genes were investigated. Genes involved in color development: PSY1, CRTISO, GGPPS2, and DXS; cell-wall modification: PG, PE1, TBG4, LeEXP1, and XTH5; and volatile biosynthesis: TomloxC, ADH2, and ATT, were down-regulated by chilling. The alteration of ethylene production correlated with the altered ACS2, ACS4, and ACO1 expression. The expression of genes involved in ethylene signal transduction pathway such as LeETR1, NR, LeETR4, LeCTR1, LeEIL3, LeEIL4, and LeERF3 was altered by chilling. The gene expression of LeMADS-RIN, a ripening-regulated transcription factor, was down-regulated by chilling. The microarray analysis suggested other transcription factors may be involved in altered fruit ripening associated with CI. In conclusion, IL 11-2 tomato had the potential of being used as a model to study of the effects of chilling in fruit ripening. How chilling affects fruit ripening at the transcriptional and posttranscriptional levels should be studied in this tomato

Effect of Feed Supplement Containing Dried Kratom Leaves on Apparent Digestibility, Rumen Fermentation, Serum Antioxidants, Hematology, and Nitrogen Balance in Goats

The objectives of the present study were to examine the influence of supplementation with dried kratom leaf (DKTL) on the performance, hematology, and nitrogen balance in goats. Four 12-month-old male crossbred (Thai Native x Anglo Nubian) goats with an initial body weight (BW) of 24.63 ± 0.95 kg were allocated randomly to receive four different levels of DKTL using a 4 × 4 Latin square design. The DKTL was added to a total mixed ration (TMR) diet with doses of 0, 2.22, 4.44, and 6.66 g/day to investigate the treatment’s efficacy. The DKTL was high in secondary metabolites, including mitragynine, total phenolics, total tannins, flavonoids, and saponins. There were quadratic effects on total DMI in terms of kg/day (p = 0.04), %BW (p = 0.05), and g/kg BW.75 (p = 0.02). DKTL increased apparent digestibility with quadratic effects (DM; p = 0.01, OM; p = 0.01, CP; p = 0.04, NDF; p = 0.01, and ADF; p = 0.01). The pH value was within the rumen’s normal pH range, whereas NH3-N and BUN concentrations were lower with DKTL supplementation, and also reduced cholesterol (CHOL, p = 0.05) and low-density lipoprotein (LDL, p = 0.01). The protozoa population decreased linearly as DKTL levels increased (p < 0.01), whereas Fibrobacter succinogenes increased quadratically at 0 h (p = 0.02), and mean values increased linearly (p < 0.01). The average value of acetic acid (C2) and methane production (CH4) decreased linearly (p < 0.05) when DKLT was added to the diet, whereas the quantity of propionic acid (C3) increased linearly (p = 0.01). Our results indicate that DKTL could be a great alternative supplement for goat feed. We believe that DKTL could provide opportunities to assist the goat meat industry in fulfilling the demands of health-conscious consumers