Volume 3, Issue 1

Empiric equations for the determination of the equilibrium moisture content as a function of temperature and relative humidity of air are normally obtained from experimental data by curve fitting. Once the fitting parameters of a function for a given product are determined, the value of that function for specific values of temperature and humidity of air is obtained by substituting these values into the function, which represents an indirect measurement. Generally, the results of these modelings are stated without the uncertainties inherent in the measurement. This article proposes a method for the determination of these uncertainties. For that, a computer code was developed which calculates the error propagation in first order approximation from the obtained fitting parameters and their covariances. The code was used for the determination of the uncertainties of the equilibrium moisture content of pumpkin seed flour, both for adsorption and desorption. This procedure allows a report of the measurement in agreement with the rules established by international standardization organizations.

The ICUMSA or AOAC (Association of Official Agricultural Chemists) traditional test methods for testing individual constituents, pol and brix, are time consuming, operator dependent and involve the use of hazardous chemicals. The increased awareness of environmental and health topics makes it desirable to avoid the clarification of cane juice with basic lead acetate. Widely used in the food and agricultural industries, Near Infrared Spectroscopy NIR has now made considerable inroads into the more lengthy and wet chemistry procedures. Near Infrared is the region of combination bands and overtones due to interatomic forces. Hydrogenic atoms being the lightest vibrate within the near infrared region due to N-H, O-H and C-H groups. These are common atoms present within most food products. As near infrared wavelengths are specific, individual components can be identified so it can be used for quantitative analysis of phosphates, silicates and amino acids in cane juice. Amino acids are important as they, along with other nitrogenous bodies, react with reducing sugars to form colored compounds. Analyzing amino acids in a sample can help solve color problem in sugar. Alanine and glycine are commonly found amino acids in sugarcane. In the present research the online estimation of alanine and glycine is done in cane juice using Near-Infrared spectroscopy. Near Infrared Spectrophotometer of Elico (India) range (600-2500nm) has been used in its transmittance mode in conjunction with two multivariate calibration procedures, i.e., Partial Least Square Regression analysis (PLSR) and Stepwise Multivariate Linear Regression analysis (SMLR) for the analysis of alanine and glycine in cane juice. Multi linear regression analysis was also carried out to find out the most correlating wavelengths along with the standard deviation.

The effects of ingredients on the sensory evaluation and rheological behavior of two brands of mayonnaise were examined in this work. Mayonnaise samples were examined by Analytical Descriptive Test and Ranking Test of Preference. The rheological parameters were determined at 25°C using a concentric cylinder Brookfield rheometer with a spindle SC4-34. The results showed that standard mayonnaise as opposed to low-fat mayonnaise gained higher grades for most sensory attributes. All samples were found to exhibit non-Newtonian pseudoplastic behavior described by Herschel–Bulkley model. A decrease in the yield stress, viscosity and shear stress with the decrease in oil content was observed in all products, which confirm that the rheological characterization is capable of distinguishing rather well between mayonnaises made with different formulation.

The friction factors (f) for Newtonian, power law, Bingham plastic and Herschel-Bulkely fluids were predicted after developing and training four neural networks (NN). Three and four layer NN and Wardnet slab were used for f predictions. When average velocity (u), pipe diameter (D), fluid density and fluid viscosity were used for predicting f values for Newtonian fluids, average absolute error was only 0.00004 with standard deviation of 0.00050 and correlation coefficient (r) of 0.9981. When using flow behaviour index (n),u, D, density and consistency coefficient (k) as inputs of an NN for power law fluids, the average absolute error of predicting f was 0.0116 with r of 0.9998. For prediction of f using yield stress, u, D, density and plastic viscosity as inputs to an NN for Bingham plastic fluids, the average absolute error was 0.0044 with r of 0.9961. The average absolute error was 0.0169 with r of 0.9996 for the prediction of f taking n, yield stress, u, D, density and k as inputs to an NN for Herschel-Bulkely fluids. Inputs except n and density and output were transformed on a logarithmic base to 10 scale. Prediction using log f or extension of f limit reduced prediction errors.

A study was conducted to evaluate the parameters affecting the dewatering of cassava mash during processing. First, studies on the pressure distribution within the mash during the dewatering were carried out. Experimental equipment consisting of tyre tube filled with water, a copper tube, and a pressure gauge was designed and fabricated to measure pressure used in expressing the juice contained in the grated cassava mash. It also included a cylindrical dewatering tank made of galvanized steel plate and a sack which was used as control. The tank had 7mm holes drilled at the base to allow the flow of juice. The volume of juice was measured using a measuring cylinder and the stopwatch measured the time. IITA TMS 4(2) 1425 variety of cassava at three levels of maturity age of 9, 12 and 15 months was utilized in the study. The dewatering pressure is from hydraulic jack used to press the grated mash. The dewatering parameters investigated were pressure drop, face area of the filter medium and mash resistance. The results showed that mash resistance varied with the age of the cassava with the highest value of 54,000,000,000 m/kg recorded. Medium Resistance also varied with the age, 33,000,000,000/m was the highest value recorded for 15 months old sample. 0.00371m3 volume of filtrate was obtained from the 12 months old sample with 0.0945 kg mash cake deposit on the filtering medium as the highest deposit. The Kozemy constant value for TMS 4(2) 1425 variety of cassava was found to be 11400000 and Porosity 0.0181, the result presents the distribution and values of identified parameters numerically for equipment designers use.

Pork quality is usually determined subjectively as PSE, PFN, RFN, RSE and DFD based on color, texture and exudation of the meat. In this study, a hyperspectral-imaging-based technique was developed to achieve rapid, accurate and objective assessment of pork quality. The principal component analysis (PCA) and stepwise operation methods were used to select feature waveband from the entire spectral wavelengths (430 to 980 nm). Then the feature waveband images were extracted at the selected feature wavebands from raw hyperspectral images, and the average reflectance (R) was calculated within the whole loin-eye area. Artificial neural network was used to classify these groups. Results showed that PCA analysis had a better performance than that of stepwise operation for feature waveband images selection. The 1st derivative data gave a better result than that of mean reflectance spectra data. The best classified result was 87.5% correction. The error frequency showed that RSE samples were easier to classify. The PFN and PSE samples were difficult to separate from each other.

The direct ohmic heating has been one of modern heating technology at which an electrical current passing directly through an electrically conductive medium generates the heat. During milk ohmic heating fouling deposits can be formed due to milk protein degradation. The fouling removal requires periodical cleaning that increases costs of energy, detergents and wastewater treatment.Simple semiempirical generalized correlation quantifying the effect of concentration and temperature onto electrical conductivity was proposed and tested on published data of milk, coffee and aqueous H2TiF6 solution. The semiempirical fouling kinetics model was proposed and verified in direct batch ohmic heating of milk. The model is based on the analogy to mechanisms and chemical kinetics of serial reactions. The effect of flowrate onto the fouling formation in continuous direct ohmic heating of milk was investigated. The proposed empirical fouling kinetics model is based on the assumption that the growth rate of the fouling layer thickness depends on time exponentially. It was found that fouling layer growth intensity was not decreased by the higher wall shear stress induced by the higher flowrate. However increasing wall shear stress enlarged the maximal time tnf in which the fouling layer growth is negligible.

Three groups of bread flavor such as bread flavor I (alcohol odor), bread flavor II (bread odor), and bread flavor III (baked odor) are successively generated from dough in the breadmaking process. We could observe these flavors and intensities by sensory test, and measured the amounts of each flavor by the Odor Intensity Indicator (O I I). When oven-temperature was increased from 190 to 230 °C, the general profiles of appearance of bread flavors were changed to earlier time in the breadmaking process, and the amount of bread flavor II was gradually decreased. When bread dough was increased from 25 to 75g, the amount of total bread flavors and the bread flavor II increased quantitatively. Increase of the amount of yeast from 8.7 to 17.4 g per 515 g dough did not affect the amount of the bread flavor II. When sugar was increased from zero to 14.5 and 29.0 g per 515 g dough, the amount of bread flavor II was unchanged and decreased, respectively. When salt was increased from zero to 2.9 and 5.8 g per 515 g dough, the amounts of bread flavors were successively increased, but the bread flavor II only increased with 2.9 g salt-dough. Bread flavor II could be fixed in liquid oil under these optimum breadmaking conditions.