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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.

In order to form large micro-droplet-arrays, we have developed a device that can merge and transport microdroplets in two directions. Transportation of droplets is performed by electrostatic actuation technique. The speciality of this method is that it uses only one electrode panel, based on standard printed circuit board (PCB), and in it, only 18 independent controls are needed. We have also developed disposable plastic films cards, which can substantialy reduce the development cost because the actuation chip has been separated into two parts: a fixed electrode panel and a less costly removable card. The droplets array is formed and analyzed in the card.

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.

New methods for improving the quality of protein crystals are always being sought. Electric-field-induced protein crystallization is one of them. A few devices have already been developed. We conducted a series of experiments for several years and fabricated many electrode panels to realize a device for electric-field induced protein crystallization for the microbatch method. The review mainly deals with the application of the various devices that have so far been reported in the literature on the subject, including an overview of the work that has already been conducted. The factors affecting the electric-field-induced protein crystallization are also discussed.

Microbial control of postharvest diseases has been extensively studied and appears to be a viable technology. Food safety must be ensured at each postharvest processing step, including handling, washing of raw materials, cleaning of utensils and pipelines, and packaging. Several commercial products are available for this purpose. The time is ripe for developing new techniques and technologies. The use of electrolyzed water (EW) is the product of a new concept developed in Japan, which is now gaining popularity in other countries. Little is known about the principle behind its sterilizing effect, but it has been shown to have significant bactericidal and virucidal and moderate fungicidal properties. Some studies have been carried out in Japan, China, and the USA on the pre- and postharvest application of EW in the field of food processing. EW may be produced using common salt and an apparatus connected to a power source. As the size of the machine is quite small, the water can be manufactured on-site. Studies have been carried out on the use of EW as a sanitizer for fruits, utensils, and cutting boards. It can also be used as a fungicide during postharvest processing of fruits and vegetables, and as a sanitizer for washing the carcasses of meat and poultry. It is cost-effective and environment-friendly. The use of EW is an emerging technology with considerable potential.

Single bite and double bite tests were performed on mango fruit, cv. Pelican, with the Texture Analyser (TA-XT2) and the effect of the degree of compression from 10% to 90% on Texture Profile Analysis (TPA) parameters was measured at a compression speed of 0.5 mm/s. Hardness 1, hardness 2, area 1, area 2, adhesiveness, and chewiness increased with increasing compression but the rate of increase varied widely. The area and width of the second bite were much smaller than those of the first bite indicating low cohesiveness and low springiness. Springiness, cohesiveness and resilience decreased as compression increased. Texture profile data were used to develop regression models for dependent variables -hardness, cohesiveness, springiness, resilience, adhesiveness, and chewiness. The relationship could best be explained by quadratic function for hardness 1, hardness 2, area 1, area 2, cohesiveness, resilience, and chewiness; whereas it was cubic for adhesiveness and springiness. The textural properties of Pelican mango fruit were significantly affected by the degree of compression, i.e., up to 30% compression no remarkable change in the height of the tested mango cylinders was observed, while from 40 to 60% compression the height was reduced and compression over 70% destroyed the shape of the samples. It is recommended to use 70% compression for single bite test for mango and less than 30% for the TPA test. Since the TPA parameters vary widely with degree of compression, it is recommended that the degree of compression be reported, and/or, if possible, to standardize it.

The effect of amount of manure (animal dung) on the texture of muskmelons (Cucumis melo L.) has been studied. Melons were grown in a greenhouse with 20 and 50 t·ha-1 of manure. Melons were harvested four times at 4-day intervals and kept at ambient conditions for about 8-12 days. Texture was determined by using “Firm Tester” that employs acoustic technology and to provide a firmness index expressed as transmission velocity [meters per second (m/s)]. At the time of the first, second, third and fourth harvest the fruit grown with 20 t·ha-1 manure gave mean transmission velocities of 54.5 ± 2.5, 55.2 ± 5.7, 49.6 ± 4.8, and 46.8 ± 9.4 m/s, respectively. Linear regression equations for fruit grown with 20 t·ha-1 manure showed that the fruit from the first harvest took 10 days to reach 40 m/s, while fruit from the second, third and fourth harvest took 11, 9.5, and 4 days, respectively, to reach this index. The corresponding values for fruit grown in 50 t·ha-1 of manure were 7.5, 10, 5.5 and 4.5 days, those from the second harvest gave the best keeping quality. The firmness index of melon grown in 20 t·ha-1 of manure was greater than that grown in 50 t·ha-1 manure. Higher soil NO3-N contents were associated with softer melons. The correlation between panelist scores for texture and the firmness index was 0.907. Both °Brix and panelist scores for sweetness indicated that manure did not affect the sweetness of melon. The digital firmness tester could detect the effect of manure on the texture of the melons, and could be used to determine the appropriate time of harvest for each and every individual melon.

Mangoes (Mangifera indica L., cv. ‘Irwin’) grown in plastic greenhouses in the Okinawa Islands, Japan, were obtained and stored at 5°C, 10°C, 15°C, and in ambient conditions (20°C to 25°C) for 21 days. Their sound velocity was recorded by an instrument named the “Firm Tester,” which uses an acoustic transmission technique to indicate firmness index as a function of transmission velocity (TV). Magnitude of TV indicates fruit firmness. As the storage period advanced, the transmission velocity decreased. It was evident that ripened mangoes could be stored at 5°C without occurrence of chilling injury (CI), but non-ripened mangoes stored at the same temperature showed signs of CI. The Firm Tester provided a true firmness index of Irwin mangoes non-destructively. Commercialization of the Firm Tester could help the growers, packers, and retailers judge the firmness of fruit non-destructively.

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.

A new device has been fabricated for electric field-induced protein crystallization with the microbatch method. In conjunction with this, a specialized tray using inexpensive plastic film has been developed for economical set-up of the experiments. Crystallization can be conducted using AC or DC voltage.

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.

A study was carried out to evaluate the effectiveness of ionizing radiation in eliminating Escherichia coli O157:H7 and Salmonella on commercial ready-to-eat radish and mung bean sprouts and to assess the chemical and physical quality of these sprouts. The use of ionizing radiation was investigated as a means of reducing or totally inactivating these pathogens, if present, on the sprouts. Treatment of mung bean and radish sprouts with a dose of 1.5 and 2.0 kGy, respectively, significantly reduced E. coli O157:H7 and Salmonella to nondetectable limits. The total vitamin C content was gradually reduced with the increase in irradiation dose (P < 0.0001). However, the effect of storage interval on the loss of vitamin C was nonsignificant for radish sprouts and significant for mung bean sprouts (P < 0.04). The color, firmness, and overall visual quality of the tested sprouts were acceptable when effective doses were applied to both radish and mung bean sprouts. Therefore, ionizing radiation could be useful in reducing the population of pathogens on sprouts and yet retain acceptable quality parameters.

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.

In Japan, cost of production of fruits is exorbitantly high and reduction of postharvest losses is of the prime importance. An objective, non-destructive technique is needed to field test ripeness of fruits. Use of such a technique during picking would help to assure that consistent quality is being delivered to marketers, retailers, and consumers. Sonic and vibration response method is one technique for predicting the textural quality of agricultural products non-destructively. Experiments on use of this technology to symmetrical fruits, like melons and water-melons, have been reported. In the present study, a non-symmetrical fruit, i.e., mango was used to determine whether it can be used or not? Orientation of the mango fruit is important to have reliable data. It was also found that the best place to measure firmness by Acoustic Firm Tester is the thick flat pulpy side of the mango fruit. This tester would be beneficial especially in those countries where retail price of locally produced fruits is very high due to high cost of production, and also to other countries where quality is given prime importance.

Food Safety has to be ensured at each processing step including handling, washing of raw materials, cleaning of utensils/pipelines, packaging, etc. Different techniques are applied to achieve this task. Use of Electrolyzed water is the product of a new concept developed in Japan and getting popularity in other countries as well. Little is known about its principle of having sterilization effect. There are different schools of thought. Some believe it is presence of chlorine species, others believe on its low pH. Few papers emphasized that it is due to its high Oxidation Reduction Potential (ORP) and some says that it the mixture of all these points. But the fact remains that it possesses high bactericidal, virucidal, and moderate fungicidal properties. Some studies have been carried out in Japan, China, and USA on application of Electrolyzed Water in the field of food processing. This is an emerging technology with a lot of potential. It is cost effective and possesses environment friendly properties. To produce it, an apparatus is required that utilizes common salt and an electric source. It can be produced at site, as the size of the machine is quite small. Studies have been done on its use as a sanitizer for fruits, utensils, and cutting boards. It can also be used as a fungicide at postharvest processing of fruits and vegetables, and as a sanitizer for washing carcasses of meat and poultry.