THE INFLUENCE of FIELD STRENGTH, SUGAR and SOLID CONTENT ON ELECTRICAL CONDUCTIVITY of STRAWBERRY PRODUCTS

Castro, Inês; Teixeira, J. A.; Salengke, Salengke; Sastry, Sudhir K.; Vicente, António A.

doi:10.1111/j.1745-4530.2003.tb00587.x

Cited by 96 publications

(63 citation statements)

References 12 publications

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“…The linear relationship between EC and temperature (with R 2 ranging from 0.90 to 0.92) is also presented in Table 1. These findings were observed to be in agreement with the reported observations for ohmic processing of lean beef, strawberry products, chicken breast, peach/apricot purees and for fresh fruits, respectively [4,9,16,24,31]. The observed increase of EC at high temperature could be attributed to the ionic mobility [16].…”

Section: Ohmic Heating Of Raw Rice Bransupporting

confidence: 82%

Stabilization of Raw Rice Bran using Ohmic Heating

Dhingra

Chopra

2012

Agric Res

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Ohmic heating experiments for heating of raw rice bran were conducted using a Teflon cylindrical cell. Electrical conductivity (EC) values were evaluated for ohmic heating of rice bran at 20, 30, and 40 % moisture content (w.b.), by applying voltage gradients between 44 and 72 V/cm. The EC increased significantly with increase in temperature and moisture content but the variation in EC was not significant with the variation in voltage gradient. The linear temperature and moisture content-dependent EC relations were obtained. EC values for rice bran at 20 % moisture content were in the range 0.01-0.06 S/m within the entire temperature range of 25-100°C. Whereas, they were observed to be 0.04-0.14 and 0.08-0.23 S/m, respectively, for rice bran at 30 and 40 % m.c., w.b. An ohmic heating system having a capacity of 10 kg/batch was developed and evaluated for its performance. Ten kg rice bran was hydrated and heated by flow of electric current through it. The treated sample was observed to be stable even after 75 days of storage in comparison to raw rice bran sample. The % free fatty acid (FFA) in treated (ohmically heated) bran was observed to be 4.77 % after 75 days of storage whereas it was 41.84 % in case of raw bran. The FFA concentration of the ohmically heated samples increased very slowly in comparison to raw rice bran samples during 75 days of storage. The peroxide value and acid value of ohmically heated samples after 75 days of storage were 4.7 meq/kg and 9.34 %, respectively. Results showed that ohmic heating is an effective method for rice bran stabilization.

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Section: Ohmic Heating Of Raw Rice Bransupporting

confidence: 82%

Stabilization of Raw Rice Bran using Ohmic Heating

Dhingra

Chopra

2012

Agric Res

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“…In this sense, this technology provides processed products of higher quality (i.e. where such thermal labile compounds as proteins and vitamins can be preserved) than those obtained by conventional heating technologies (Castro, Teixeira, Salengke, Sastry, & Vicente, 2003;Machado, Pereira, Martins, Teixeira, & Vicente, 2010;Parrot, 1992). During OH treatment, electric current passes through food that behaves as a resistor in an electrical circuit, and heat is internally generated according to Joule's law (De Alwis & Fryer, 1990).…”

Section: Introductionmentioning

confidence: 99%

Influence of moderate electric fields on gelation of whey protein isolate

et al. 2015

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Proteins are one of the food constituents most affected by heating, and some of the changes involve their unfolding, denaturation and gelation. Ohmic heating has often been claimed to improve the quality of foodstuffs due to its uniform heating and (putative) presence of a moderate electric field (MEF). However, this is still subject to discussion, so it is important to determine the effect of ohmic heating and of its MEF upon food constituents. Hence, the aim of this work was to evaluate the effects of MEF on denaturation, aggregation and viscoelastic properties of whey protein isolate (WPI), and compare them with those obtained via conventional heating under identical treatment conditions (up to 30 min at 85 o C). Results have shown that MEF interferes with whey protein unfolding and aggregation pathways at relatively high temperatures. MEF treatments have resulted in WPI solutions possessing more 8 and 10% of native Lactoglobulin and Lactalbumin, respectively, after 30 s of heating at 85 o C, when compared with a conventional heating method. Protein aggregates from MEF-treated WPI solutions presented a maximum increase in size of 78 nm, whereas conventional heating produced an increase of 86 nm. Unlike in conventional heating, aggregation of whey proteins during MEF was not sufficiently strong to form a true elastic gel network, since decreases in both storage and loss modulus were observed following MEF treatment. Our results suggest that MEF may provide a novel method for production of a whey protein matrix with distinctive gel-forming properties.2

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“…In the 1980s, the technology was once again revived and has achieved some industrial applications, including the pasteurization of liquid eggs and the processing of fruit products (Sastry, 2007). Recently, the world's food industry has focused increasing attention on ohmic heating of pumpable food because the products obtained are of clearly superior quality than those processed by conventional technologies (Castro et al, 2003). Now this processing technology is being used throughout the world on a wide variety of products.…”

Section: Introductionmentioning

confidence: 99%

“…Apparently due to the lack of inert materials for the electrodes this technology was abandoned (Castro et al, 2003). In the 1980s, the technology was once again revived and has achieved some industrial applications, including the pasteurization of liquid eggs and the processing of fruit products (Sastry, 2007).…”

Section: Introductionmentioning

confidence: 99%

Ohmic Heating Behavior of Certain Selected Liquid Food Materials

Kong¹,

Liu²,

Wang³

et al. 2008

International Journal of Food Engineering

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Ohmic heating is an alternative fast heating technique for food products, which takes its name from Ohm's law. The basic principle of ohmic heating is the conversion of electrical energy into heat, resulting in internal energy generation. In this study, an experimental ohmic heating unit was designed and fabricated. Four kinds of liquid food materials (tap water, fruit-vegetable juice, yogurt and 0.5% aqueous sodium chloride solution) were heated on this laboratory scale static ohmic heater to evaluate the device's performance. Different voltage gradients (7.5V/cm, 11.25V/ cm, 15V/cm, 18.75V/cm, 22.5V/cm and 26.25V/cm) were applied to study the heating behavior of liquid food materials. Results indicated that the voltage gradient significantly influenced the ohmic heating rates for all four materials tested. The electrical conductivity also changed significantly with temperature.

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THE INFLUENCE of FIELD STRENGTH, SUGAR and SOLID CONTENT ON ELECTRICAL CONDUCTIVITY of STRAWBERRY PRODUCTS

Cited by 96 publications

References 12 publications

Stabilization of Raw Rice Bran using Ohmic Heating

Stabilization of Raw Rice Bran using Ohmic Heating

Influence of moderate electric fields on gelation of whey protein isolate

Ohmic Heating Behavior of Certain Selected Liquid Food Materials

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