Relationships Between Color, Trypsin Inhibitor Contents, and Urease Index of Soybean Meal and Effects on Broiler Performance

Publisher Summary This chapter organizes the development of instrumental methods for measuring food quality as a distinct discipline. As food quality is ultimately evaluated by the human consumer, it appears logical to organize the material in accordance with the human senses involved in the evaluation. Thus, quality measurements may be classified into categories of: appearance as observed by the eye; kinesthetics as felt by hand or mouth; and flavor as tasted and smelled by the mouth and nose. Factors that are included in the appearance category are items such as size, shape, pattern, wholeness, and consistency. Most of these may be measured easily by relatively simple devices such as scales, screens, micrometers, planimeters, sedimentation tests, consistometers, or displacement in liquid media. Another approach is through the employment of photographs, models, and drawings. For measuring color and gloss, methods such as munsell color system, hunter color and color difference meter, and abridged methods have been adopted. Viscosity or consistency is an appearance factor of great importance with food products such as catsup, juices, creams, fruit preserves, jams, jellies, gelatins, oils, and dough. Of the many instruments in existence for the measurement of viscosity and consistency, one of the most widely used methods for determining the viscosity of pure fluids is Poiseville. Various measuring units for size and shape have been illustrated. As defects are another factor of quality evaluated by the consumer's eye, the chapter discusses its classification and available instruments for measuring the defect factor. Kinesthetics characteristics that deal with the sense of feel have been discussed and its classification has been described. Measurement of specific flavor constituents that are divided into taste and odor categories have also been discussed.

Principles and Instrumentation for the Physical Measurement of Food Quality with Special Reference to Fruit and Vegetable Products

The colour of 112 Moroccan honeys was assessed by tristimulus colorimetry based on their diffuse reflectance spectra with a white background and a black background, with the application of the equations by the non-uniform colour space CIE Y10 X10 Y10, and by the uniform colour space CIELAB proposed by the Commission Internationale de l'Eclairage (CIE). As the weighted-ordinate method (Ay = constant) establishes, the visible reflection spectra of the samples is weighted according to the characteristic factor of the selected visual reference conditions, 10° visual field observer and CIE standard illuminant D65. The results obtained by the discriminant analysis of the results revealed that the unifloral honeys studied (eucalyptus, orange, heather and mint) were better characterized when measured in the CIELAB colour space against a white background (93% correct) than using a black background (66%). (A)

Chromatic Characterisation of Moroccan Honeys by Diffuse Reflectance and Tristimulus Colorimetry: Non-uniform and Uniform Colour Spaces

This research was carried out to determine how honey samples are grouped based on physicochemical characteristics A total of 36 honey samples, collected from January of 1999 to June of 2000, in the northern coast of Bahia State, were evaluated with regard to humidity, color, protein, pH, acidity, formol index, electrical conductivity, ash, diastase number, hydroxymethylfurfural (HMF), total sugar, reducing sugars, sucrose, and types of pollen The results indicate that HMF, reducing sugar and total sugars are the characteristics that most influenced the grouping Two plant genera, Eucalyptus and Mimosa, were observed as predominant bee plants in the region

Análises multivariadas com base nas características físico-químicas de amostras de méis de Apis mellifera L. (Hymenoptera: Apidae) da região litoral norte no estado da Bahia 1

SummaryMeasurement of the optical density of honey with a colorimeter using the complete light spectrum offers a precise, reproducible method for classifying honey according to its colour. The method can be used for honeys from most floral sources, and provides a practical systematic basis for blending honey to any required colour.

Optical Density as a Means of Colour Classification of Honey

Glass Color Standards for Extracted Honey

Previous official color standards for maple sirup, designated Light Amber, Medium Amber, and Dark Amber, were solutions of sugar caramel in glycerin standardized in terms of transmittance at 560 mμ. These solutions were not satisfactory because of instability of color and inconvenience of repeated preparation. Glass color standards were accordingly developed to match the chromaticities of fresh standard solutions in 31.5 mm depth. An improved color comparator was devised for use with the glass standards. The caramel-glycerin solutions and maple sirups were characterized spectrophotometrically and in terms of several one-dimensional color scales in use in the sugar industry. Complete specifications for the standard solutions and new glass standards are presented in the CIE system. Color tolerances were established in MacAdam units of chromaticity difference and a simple one-wavelength method of testing glasses for the production of duplicate standards was developed.

B. A. Brice

Papers

Glass Color Standards for Extracted Honey

Glass Color Standards for Maple Sirup