Thermophysical Properties of Lemon Juice as Affected by Temperature and Water Content

Journal of Chemical & Engineering Data (Impact Factor: 2.05). 08/2009; 54(8). DOI: 10.1021/je900155c

ABSTRACT To design equipment for food processing and estimate process times for refrigerating, freezing, heating, or drying of foods, the thermophysical properties must be known. Since the thermophysical properties of foods are strongly dependent upon chemical composition and temperature, composition and temperature based models provide a means of estimating these properties. In this work, the thermophysical properties of lemon juice were determined at a water mass fraction of (0.381 to 0.900) and a temperature of (273.45 to 353.75) K. Density and thermal conductivity varied from (962.3 to 1282.8) kg·m−3 and (0.344 to 0.624) W·m−2·K−1, respectively. Heat capacity and thermal diffusivity varied from (2446.5 to 4060.1) J·kg−1·K−1 and (0.1160·10−6 to 0.1785·10−6) m2·s−1, respectively. Simple polynomial functions were fitted to the experimental data, and good agreements were obtained. In the tested range, water content showed greater influence on the thermophysical properties.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Thermophysical properties of enzyme clarified lime (Citrus aurantifolia L.) juice were evaluated at different moisture contents ranging from 30.37 % to 89.30 % (wet basis) corresponding to a water activity range of 0.835 to 0.979. The thermophysical properties evaluated were density, Newtonian viscosity, thermal conductivity, specific heat and thermal diffusivity. The investigation showed that density and Newtonian viscosity of enzyme clarified lime juice decreased significantly (p < 0.05) with increase in moisture content and water activity, whereas thermal conductivity and specific heat increased significantly (p < 0.05) with increase in moisture content and water activity and the thermal diffusivity increased marginally. Empirical mathematical models were established relating to thermophysical properties of enzyme clarified lime juice with moisture content/water activity employing regression analysis by the method of least square approximation. Results indicated the existence of strong correlation between thermophysical properties and moisture content/water activity of enzyme clarified lime juice, a significant (p < 0.0001) negative correlation between physical and thermal properties was observed.
    Journal of Food Science and Technology -Mysore- 11/2012; 51(11). DOI:10.1007/s13197-012-0866-x · 2.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to design and to adapt equipments for food processing, it is essential to know thermophysical properties. Once temperature and composition affects these properties, models based in such factors are important for further calculation. In this work, density and dynamic viscosity of bovine milk, probably the most processed food fluid in the world, were determined within large ranges of temperature and major constituents (moisture, fat, lactose, protein and minerals), based on typical processing values. Density varied from (962.01 to 1100.45) kg/m(3) and dynamic viscosity varied from (0.60 to 63.70) mPa(.)s. Temperature and moisture content negatively affected both properties, while lactose, protein and minerals contents positively affected them. An increase in fat content reduced density and increased dynamic viscosity. Experimental density data were fitted to the simplest multiple linear model and dynamic viscosity data were fitted to a multiple type Arrehnius' model, obtaining good agreement.
    International Journal of Food Engineering 01/2012; 8(1). DOI:10.1515/1556-3758.1860 · 0.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Export Date: 15 February 2013, Source: Scopus, Art. No.: 8
    International Journal of Food Engineering 01/2012; 8(3). · 0.46 Impact Factor


Available from
Jun 5, 2014