The Effects of Pasteurization by Conventional and Ohmic Heating Methods and Concentration Processes on the Madan (Garcinia Schomburgkiana Pierre) Juice Properties

2020 ◽  
Vol 36 (2) ◽  
pp. 205-219
Author(s):  
Krittiya - Khuenpet ◽  
Weerachet - Jittanit
Keyword(s):  
Electrical Conductivity ◽  
Mathematical Models ◽  
Color Change ◽  
Ohmic Heating ◽  
Conventional Heating ◽  
Heating Method ◽  
Electrical Conductivities ◽  
Juice Concentrate ◽  
Filtration Step

HighlightsThis research proved that Madan juice should be filtered before pasteurization in order to be more palatable for consumer.Madan juices and its concentrates can be efficiently heated by ohmic method due to their high electrical conductivities.Mathematical models developed in this study can accurately predict the electrical conductivity of the Madan juice during ohmic heating.This research proved that the quality of pasteurized Madan juice concentrates was rather steady during 60 days of storage.Abstract.Madan is a native fruit of the Southeast Asian region. The objectives of this research were: 1) to investigate the effect of pasteurization methods on the qualities of Madan juices and 2) to examine the influence of ohmic heating on the qualities and storage stability of pasteurized and concentrated juice compared to conventional heating method. It appeared that Madan juices (5-27.2 °Brix) can be heated by ohmic method due to high electrical conductivities (1.37-4.74 S.m-1). Mathematical models developed in this study can precisely predict the electrical conductivity of Madan juice. Filtration step and pasteurization condition of 95°C for 15 s should be applied in Madan juice processing because they provided the highest sensorial scores and the lowest color change. The continuous-mode machine provided the lightest color with low redness and yellowness values. Quality changes of Madan juice concentrate samples pasteurized using double jacket kettle and ohmic heating method were diminutive during 60 days of storage. Keywords: Concentration, Juice, Madan, Ohmic heating, Pasteurization.

Correlation of Electrical Conductivity and Thermal Properties of Native Starch during Ohmic Heating

2011 ◽  
Vol 7 (5) ◽  
Author(s):  
Lam-Lam Wong ◽  
Yong-Wei Xu ◽  
Zhan-Hui Lu ◽  
Li-Te Li
Keyword(s):  
Electrical Conductivity ◽  
Room Temperature ◽  
Ohmic Heating ◽  
Heating Process ◽  
Rapid Evaluation ◽  
Scanning Calorimetry ◽  
Heating Method ◽  
Starch Gelatinization ◽  
On Line ◽  
Water Ratio

Electrical conductivity of starch suspension during ohmic heating was applied to analyze the starch gelatinization process. Native starches from wheat, corn, rice, potato, sweet potato, and pea were prepared on a starch to water ratio of 1:3 (w/w) with adding 0.05 M potassium chloride. A laboratory scale ohmic heating setup was designed to heat the starch suspension from room temperature to 90°C at a controlled heating rate of 10°C/min operating at 50 Hz and 110 V. The results show that starch gelatinization temperatures could be precisely calculated from electrical conductivity of starch suspension during ohmic heating process. The starch gelatinization temperatures based on ohmic heating were comparable to those measured by differential scanning calorimetry (DSC). Highly significant correlation of onset temperature (R=0.9972) and peak temperature (R=0.9950) were observed. The ohmic heating method could provide an alternative way to DSC with a promising potential for on-line and rapid evaluation of starch gelatinization temperatures.

Ohmic and Conventional Heating of Pomegranate Juice: Effects on Rheology, Color, and Total Phenolics

2009 ◽  
Vol 15 (5) ◽  
pp. 503-512 ◽  
Author(s):  
H. Yildiz ◽  
H. Bozkurt ◽  
F. Icier
Keyword(s):  
Rheological Properties ◽  
Ohmic Heating ◽  
Extraction Methods ◽  
Pomegranate Juice ◽  
Conventional Heating ◽  
Total Phenolic ◽  
Voltage Gradient ◽  
Fast Heating ◽  
Heating Method ◽  
Holding Period

Ohmic heating is an alternative fast-heating method especially for liquid foods. In this study, pomegranate juice samples, prepared by two different extraction methods, were heated ohmically by matching the same thermal history, with that of the conventional method. The ohmic heating application was conducted by changing the voltage gradient (10—40 V/cm) at 50 Hz. The samples were heated from 20 ° C to 90°C and held at 90 °C for different treatment times (0, 3, 6, 9 or 12 min). Although rheological properties, color, and total phenolic content (TPC) values changed at the initial heating up period, there were no significant changes during holding period (p < 0.05). Non-Newtonian (power law) rheology model had higher regression coefficient than Newtonian model, and the extraction method affected the consistency of pomegranate juice samples (p < 0.05). Color values of juice extracted from arils (APJ) was better than that of juice extracted from whole fruits (PPJ), as PPJ contained higher amount of TPC (p < 0.05). Since the heating method did not affect the rheological properties, color, and TPC values, it could be said that there was no electrical effect rather than thermal effects during ohmic heating of pomegranate juice. Ohmic heating could be recommended as an alternative fast-heating method for fruit juices.

scholarly journals Effects of cultural cycle and nutrient solution electrical conductivity on plant growth, yield and fruit quality of ‘Friariello’ pepper grown in hydroponics

2017 ◽  
Vol 44 (No. 2) ◽  
pp. 91-98 ◽  
Author(s):  
Amalfitano Carmine ◽  
Vacchio Laura Del ◽  
Somma Silvano ◽  
Cuciniello Antonio ◽  
Caruso Gianluca
Keyword(s):  
Electrical Conductivity ◽  
Ascorbic Acid ◽  
Fruit Quality ◽  
Water Consumption ◽  
Growth Yield ◽  
Late Summer ◽  
Carotene Content ◽  
Nutrient Film Technique ◽  
Electrical Conductivities

‘Friariello’ pepper (Capsicum annuum L.) was grown with nutrient film technique (NFT) in order to evaluate the effects of four nutritive solutions, at electrical conductivities (EC) of 3.5, 3.8, 4.1, 4.4 mS/cm, in two cultural cycles (winter-summer versus spring-autumn) on growth, yield and fruit quality. In the winter-summer cycle, fruit yield was significantly higher than in the spring-autumn one. The 3.8 mS/m EC resulted in the highest yield in the winter-summer crops, whereas the 4.1 mS/m EC was the most effective under the spring-autumn cycle. Water consumption was 34% higher in winter-summer than in spring-autumn season. The 3.8 mS/m EC caused the highest water consumption, whereas a 25% reduction was recorded under 4.4 mS/cm. The macronutrients absorption was the highest with 3.8–4.1 mS/cm EC and the lowest with 3.5 mS/cm. Fruits harvested in late summer and berries obtained under 4.4 mS/cm EC mostly showed the best quality. The fruit ascorbic acid and α-carotene content was higher in late summer than in late spring and all fruit antioxidants attained the highest values with 4.4 mS/cm EC.

scholarly journals Changes in Physicochemical and Bioactive Profile of Garlic Pulp by High Voltage Electric Field

2020 ◽  
Vol 8 (1) ◽  
pp. 131-143
Author(s):  
P Poojitha ◽  
K.A. Athmaselvi
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Pyruvic Acid ◽  
High Performance ◽  
Ohmic Heating ◽  
Storage Period ◽  
Conventional Heating ◽  
Voltage Gradient ◽  
Growth Study

Ohmic heating is an unconventional rapid sterilizing technique for complex food fluids. In this study, garlic pulp was ohmic heated at 13.33, 20 and 26.66 V/cm and also in conventional means. The effect of high voltage electric field-induced ohmic heating for increasing the shelf-life and maintaining the quality of garlic pulp was investigated. The physicochemical properties like pH and colour were determined and microbial growth study was carried out for both the ohmic heated and conventionally heated garlic pulp throughout the storage period. During storage, the physiochemical changes were at a rapid rate in conventionally heated garlic pulp when compared with the ohmic heated pulp. Garlic pulp ohmic heated at high voltage gradient (26.66 V/cm) could extend the storage period upto 60 days without adding preservatives. Bioactive compounds were analysed using high performance liquid chromatography and found to have 8.83 µg/mL, 30.28 µg/mL, 9.04 µg/mL of alliin, pyruvic acid and diallyl disulphide content, respectively in garlic pulp ohmic heated at high voltage gradient. Whereas, in conventional heating, alliin, pyruvic acid and diallyl disulphide are found to be 4.71 µg/mL, 22.97 µg/mL, 4.64 µg/mL, respectively

scholarly journals Effect of viscosity on electrical conductivity in liquid foods

2021 ◽  
Author(s):  
Balaji Subbiah ◽  
Ken R. Morison
Keyword(s):  
Electrical Conductivity ◽  
Ion Mobility ◽  
Ohmic Heating ◽  
Skim Milk ◽  
Ion Diffusion ◽  
Electrical Tomography ◽  
Milk Whey ◽  
Electrical Conductivities ◽  
Milk Whey Protein ◽  
Electrical Conductivity Data

The electrical conductivities of foods affect their heating with ohmic heating and microwaves, and are required for electrical tomography studies. A range of model foods consisting of solutions of sodium carboxymethyl cellulose (NaCMC), NaCMC + sugars, concentrated skim milk, whey protein and viscous sugar solutions, with various amounts of electrolytes were prepared. The electrical conductivity was measured using a parallel plate sensor connected to an RCL meter using an a.c. voltage. The conductivity was found to increase with concentration, but was reduced by the effects of viscosity on ion mobility. The conductivity was closely related to bulk viscosity for sugar solutions following the modified Walden equation, but was unrelated to the viscosity of NaCMC solutions. Instead an “ion-diffusion” viscosity was defined and calculated from the electrical conductivity data, and this was found to relate well to the expected viscosity of the solution to which ions are exposed at a molecular scale.

Electrical conductivity studies on silica phases and the effects of phase transformation

2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark
Keyword(s):  
Electrical Conductivity ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Hydrogen Charge ◽  
Charge Compensation ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Pressure System ◽  
Electrical Conductivities ◽  
Silica Phases

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

scholarly journals The Effect of Gaseous Ozone Generated by Surface Dielectric Barrier Discharge on the Decay and Quality of Stored Onion Bulbs

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1058
Author(s):  
Junghyun Lim ◽  
Jong-Seok Song ◽  
Sangheum Eom ◽  
Jung Woo Yoon ◽  
Sang-Hye Ji ◽  
...  
Keyword(s):  
Untreated Control ◽  
Color Change ◽  
Microbial Reduction ◽  
Ozone Exposure ◽  
Onion Bulbs ◽  
Gaseous Ozone ◽  
Surface Dielectric Barrier Discharge ◽  
Postharvest Loss ◽  
High Voltage Discharge

An effective and eco-friendly technology is needed to prevent postharvest loss of onion bulbs during cold storage. This study investigated the effect of gaseous ozone on the decay and quality of onion bulbs during storage at 2 °C and 70% relative humidity for two months. Gaseous ozone was adjusted to a concentration of 1.27 ± 0.024 ppm in the storage room by generating a high voltage discharge in air. After two months of storage, gaseous ozone significantly reduced the counts of aerobic bacteria (e.g., Rahnella aquatilis) and fungi (e.g., yeast and mold) in the onion bulbs by 4 log (CFU g−1) and 0.92 log (CFU g−1) compared with those of an untreated control, respectively. The microbial reduction by gaseous ozone resulted in a lower rotten rate of the onion bulbs, which was less than 20.0% compared with that of the untreated control. Moreover, the ozone exposure extended the storage life of the onion bulbs by delaying its color change and softening during storage. Our results suggest that gaseous ozone can control the decay of onion bulbs safely during storage.

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