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Tamarindus indica L. is well known for its acidic nature and allelopathic potential, but to date, little is known about its organic acids playing their role as allelochemicals. Hence, in the present study, identification, quantification, and contribution of organic acids present in its leaf extract were conducted using the principle of bioassay-guided procedure. High pressure liquid chromatography identified four organic acids, viz. citric, malic, oxalic, and tartaric acids, in its leaf aqueous extract with the predominance of oxalic acid (7.5 g kg−1 leaves fresh weight) followed by tartaric acid (7.3 g kg−1). The allelopathic activity of identified acids and aqueous extract was evaluated on lettuce seedlings growth based on the specific activity (EC50). The crude extract reduced radicle growth more adversely than hypocotyl at the concentration of 2.5 g L−1 (EC50). It hindered the normal physiological growth process through weak and curly seedlings, and necrosis of their tips. Among the identified acids, ...

The aims of this research were (a) to characterize the particle size distribution of mist particles in a spinach-storage atmosphere influenced by the nano-mist application, and (b) to investigate the influence of the nano-mist on the respiration and qualities (leaves color and moisture content) of spinach. The particle size distribution of the mist was determined at 95% RH and 20 C in a small-scale storage chamber and its influence on respiration rate, and qualities of spinach were investigated over six days of storage by comparing it with the control (without the nano-mist application). The nano-mist was found to alter the particle size distribution of the mist in a spinach-storage chamber by decreasing the total concentration and increasing the geometric mean diameter. The results suggested that the geometric mean diameter of nano-mist was larger than the water vapor appeared in air and that evaporated from the surface of spinach leaves through transpiration; and the transpiration could minimize the influence of nano-mist in modification of particle size distribution. The respiration rate was slightly lower in the first three days, but thereafter non-significant differences on respiration rate and leaves color were observed over the storage period, mainly because the spinach was stored at 20 C. However, based on the obtained results, it could be expected that the use of nano-mist has an advantage over the conventional mist humidification that always contribute to the deterioration from the microbial growth because of the large particle size deposition onto the produce surface.

To develop a real-time and non-destructive sanitation monitoring at a meat processing plant, UV–Vis reflectance spectrum analysis was applied. The sample was the lean part of a pork loin. The UV–Vis reflectance spectra and the factors of microbial contamination (i.e. plate count and ATP content) on the pork meat surface were measured for 3 or 4 days. The 2nd derivative of reflectance at 318 and 578 nm gave a high correlation with log 10 (plate count) or log 10 (ATP content), because the reflectance spectrum at 318 nm is probably related to ATP absorption and that at 578 nm is related to myoglobin pigments. Moreover, Partial least squares regression (PLSR) was developed and log 10 (plate count) and log 10 (ATP content) were predicted from the 2nd derivative of reflectance. The determination coefficients ( R 2 ) for calibration were 0.95–0.99. These results indicate the potential of utilizing UV–Vis reflectance spectrum analysis for cleanness assessment.

Cleanliness monitoring at slaughterhouses depend on traditional methods, e.g., visual inspection or swabbing. The visual inspection is not always accurate. Swabbing requires skilled workers and further plate count or ATP bioluminescence technique. To solve these problems, a rapid technique based on non-destructive UV–Vis reflectance was developed to monitor the ATP and viable cells. Samples were lean part of pork loin. The samples stored at 15 °C were analyzed at 0, 24, 48, 72, 84 and 96 h for ATP, plate count and UV–Vis reflectance. The reflectance spectra were measured from 240 to 540 nm at 20 °C, and then the area of 40 × 40 mm2 of the sample surface was swabbed for the determination of plate count and ATP amount. The plate count on the sample surface increased from the initial count of 29 to 3.2 × 107 CFU/cm2 after 84 h. The ATP amount also increased with time from the initial amount of 9.2 × 10−15 to 2.8 × 10−10 mol/cm2 after 84 h. The linear relationship was observed between the ATP amount and plate count with the determination coefficient of 0.95. The 2nd derivative of raw spectra gave a high correlation for the first 48 h with both ATP amount and viable cell count showing the determination coefficient of 0.89 and 0.83, respectively at 318 nm. The results strongly suggested that the UV–Vis reflectance spectrum analysis could be used as the real-time monitoring of ATP and/or plate count on meat surface with the optimal wavelength.

Anaerobic respiration is a major problem that causes the deterioration of fresh produce packaged under low O2 atmospheres. The problem becomes more severe and causes high losses in the packages handling at ambient conditions, especially in developing countries. In designing modified atmosphere packaging, the risk of anaerobic development greatly depends upon the accuracy of respiration rate prediction; therefore, the respiration rate model for a particular produce has to be identified. In this study, different atmospheric storage conditions in a closed system were realized to examine the adaptability of respiration rate models for spinach storage under low O2 at an expected ambient temperature of 25 °C. Six models were applied and it was found that, for aerobic conditions, the respiration rate could be described with a constant respiratory quotient by three models, viz., (a) Michaelis–Menten model without inhibition, (b) Michaelis–Menten model with uncompetitive inhibition, and (c) Langmuir adsorption model, whereas three other models, viz. (d) Michaelis–Menten model with competitive inhibition, (e) Michaelis–Menten model with noncompetitive inhibition, and (f) Michaelis–Menten with mixed inhibition could not be fitted. Among the three successful models, the Michaelis–Menten with uncompetitive inhibition was found to be the most suitable model for practical applications in developing countries where cold-chain systems are lacking. This model can be applied for the prediction of gas composition and optimize the packages, particularly to ensure the aerobic respiration.

A new dispenser made of Teflon that uses electrostatic manipulation technique to dispense nano-liter size droplets based on the electrostatic actuation mechanism has been developed. Two types of dispensers were developed, viz. a single-hole type (Teflon tube) and a multiple-hole dispenser (Teflon block). The single-hole type dispenser successfully dispensed droplets of a solution supplied by a syringe pump on an electrode panel surface; and thus the droplets become available for subsequent manipulation on the electrode panel. Based on the same principle, a compact Teflon block dispenser was designed that can simultaneously dispense five different solutions in a small area (30 mm). The size of dispensed droplets can be controlled by various factors, e.g., flow rate of solution, dispensing height, applied voltage, frequency of voltage pattern. We could dispense the droplets in the range of 55–210 ± 8 nL. This technique can be applied for automation of repetitive pipetting and screening operations in protein crystallization.

The effectiveness of hot water immersion (HWI) on peel color and the control of white rot caused by Botryosphaeria berengeriana on wound-inoculated European pears, cv. La-France, were investigated. After HWI at 40, 45, 48, 50, 52 and 54C for varying immersion periods, the pears were held at 20C, ≥ 90% RH (simulated retail conditions). The peel color (L*, a*, b*) was determined before and after HWI treatment. The dominant role of L* suggested that peel darkening was the major factor in color change of the HWI treated pears. The L* value of 54 was judged as the border line for acceptability and less than 51 resulted in browning. Similarly the critical points for a*, b*, chroma, hue and ΔE* were found to be -6, 34, 35, 100, and 8, respectively. Disease incidence recorded 7 days after treatment revealed that High Temperature Short Time (HTST) treatment of 54C for 3 min reduced incidence about 85% with good retention of color. Both temperature and immersion period are to be carefully selected to prolong shelf-life and retain the peel color quality of 'La-France' pears.

Chlorination presents one of the few chemical options available to help manage postharvest decay. Electrolyzed oxidizing (EO) water, containing free chlorine, is the product of a new concept developed by scientists in Japan. The effectiveness of pear (Pyrus communis L.) immersion in EO water on the control of Bot. rot on European pear, cv. La-France, was investigated. Four independent experiments were carried out. A wound was found necessary for infection. Wounded fruit were inoculated with 20 μl spore suspension of 5×105 conidia/ml of Botryosphaeria berengeriana, incubated for 4 h, immersed in EO water, and held at 20 °C, ⩾90% relative humidity (simulated retail conditions) for ripening and disease development. No chlorine-induced phytotoxicity was observed on the treated fruit. EO water suppressed the incidence and disease severity. The minimum incidence and severity were recorded for a 10-min immersion period. This study revealed that EO water is an effective surface sanitizer.

The fungicidal effectiveness of electrolyzed oxidizing (EO) water on peach [Prunus persica (L.) Batsch.] fruit was studied. Fruit were inoculated with a spore suspension of 5 × 105 conidia/mL of Monilinia fructicola [(G. Wint.) Honey] applied as a drop on wounded and nonwounded fruits, or by a uniform spray-mist on nonwounded fruits. Fruit were immersed in tap water at 26 °C for 5 or 10 minutes (control), or treated with EO water varying in oxidation-reduction potential (ORP), pH, and free available chlorine (FAC). Following treatment, fruit were held at 20 °C and 95% relative humidity for 10 days to simulate retail conditions. Disease incidence was determined as the percentage of fruits showing symptoms of the disease, while severity was expressed as lesion diameter. EO water did not control brown rot in wound-inoculated fruits, but reduced disease incidence and severity in nonwound-inoculated peach. Symptoms of brown rot were further delayed in fruit inoculated by a uniform-spray mist compared with the nonwounded-drop-inoculated peaches. Fruit treated with EO water held for 8 days at 2 °C, 50% RH, did not develop brown rot, until they were transferred to 20 °C, 95% RH. The lowest disease incidence and severity occurred in fruit immersed in EO water for up to 5 minutes. EO water having pH 4.0, ORP 1,100 mV, FAC 290 mg·L-1 delayed the onset of brown rot to 7 days, i.e., about the period peach stays in the market from a packing house to consumer. No chlorine-induced phytotoxicity was observed on the treated fruit. This study revealed that EO water is an effective surface sanitizer, but only delayed disease development.

The effect of mixed atmosphere of ozone and negative ions (MAONI) exposure on in vitro growth of Botryosphaeria berengeriana (de Notaris) and development of postharvest fruit rot on artificially inoculated European pear fruit, cv. La-France, were evaluated. In vitro mycelial plugs and pears, in separate experiments, were continuously exposed to MAONI (0.05 ppm ozone and 2.8x106 negative ions/cm3) at 4°C for 4, 8, 12, and 16 days, in a specially fabricated MAONI chamber, and then shifted to 20°C. In vitro radial growth of B. berengeriana during 5-day incubation period at 20°C was affected by the prior MAONI exposure. The 16 days MAONI exposure significantly reduced the growth of B. berengeriana and fruit rot disease.

We improved the CaCCO process for rice straw by its incorporation with a step of lime pretreatment at room temperature (RT). We firstly optimized the RT-lime pretreatment for the lignocellulosic part. When the ratio of lime/dry-biomass was 0.2 (w/w), the RT lime-pretreatment for 7-d resulted in an effect on the enzymatic saccharification of cellulose and xylan equivalent to that of the pretreatment at 120 °C for 1 h. Sucrose, starch and β-1,3-1,4-glucan, which could be often detected in rice straw, were mostly stable under the RT-lime pretreatment condition. Then, the pretreatment condition in the conventional CaCCO process was modified by the adaptation of the optimized RT lime-pretreatment, resulting in significantly better carbohydrate recoveries via enzymatic saccharification than those of the CaCCO process (120 °C for 1 h). Thus, the improved CaCCO process (the RT-CaCCO process) could preserve/pretreat the feedstock at RT in a wet form with minimum loss of carbohydrates.

In order to establish an efficient bioethanol production system for rice straw, we developed a novel lime-pretreatment process (CaCCO process) that did not require a solid–liquid-separation step. This process adopted a step in which after pretreatment lime was neutralized by carbonation, resulting in a final pH of about 6. CaCO3 produced by the process was kept in the reaction vessel, and no significant inhibitory effects on enzymatic saccharification and fermentation were observed. In the CaCCO process, solubilized carbohydrates, such as xylan, starch, and sucrose were also kept in the vessel, enabling high recoveries of monomeric sugars. Simultaneous saccharification and fermentation (SSF) of pretreated rice straw, 10% (g-rice straw/g-water), using Saccharomyces cerevisiae and Pichia stipitis yielded 19.1 g L−1 ethanol that was 74% of the theoretical yield from glucose and xylose. Thus, this process represents a novel pretreatment method to utilize not only cellulose but also xylan, starch, and sucrose from biomass.

Greenhouse-grown tree ripe (TR) and mature green (MG) mangoes (cv. Irwin) were exposed to high electric field treatment before 20 and 30 days of storage at 5 degrees C. MG fruits were allowed to ripen at room temperature after low-temperature storage. Fruit physical quality attributes, ascorbic acid, carotene, quercetin, total phenols, and antioxidant capacity were estimated before and after the storage period. Antioxidant capacity of fruit juice was estimated using the ferric reducing antioxidant power (FRAP) assay. Fruit firmness decreased significantly during storage. Titratable acidity decreased 20 days after storage. Total soluble solids did not change during storage. Antioxidant capacity of fruits remained unchanged up to 20 days of storage period and decreased thereafter. Total phenol and carotenes increased during storage. Antioxidant capacity of fruits was significantly correlated only to ascorbic acids. Peel color and carotenes were higher in TR fruits, whereas titratable acidity and firmness were higher in MG fruits. There was no significant difference in other parameters between the stages of picking. Electric field pretreatment affected the respiration and antioxidant capacity of TR fruits and did not have any significant affect on other parameters. TR mangoes of cv. Irwin are more suitable for low-temperature storage and can be successfully stored for up to 20 days at 5 degrees C without any significant losses in functional properties and quality attributes.