Colour Measurement and Analysis in Fresh and Processed Foods: A Review

Abstract

Colour is an important quality attribute in the food and bioprocess industries, and it influences consumer's choice and preferences. Food colour is governed by the chemical, biochemical, microbial and physical changes which occur during growth, maturation, postharvest handling and processing. Colour measurement of food products has been used as an indirect measure of other quality attributes such as flavour and contents of pigments because it is simpler, faster and correlates well with other physicochemical properties. This review discusses the techniques and procedures for the measurement and analysis of colour in food and other biomaterial materials. It focuses on the instrumental (objective) and visual (subjective) measurements for quantifying colour attributes and highlights the range of primary and derived objective colour indices used to characterise the maturity and quality of a wide range of food products and beverages. Different approaches applied to model food colour are described, including reaction mechanisms, response surface methodology and others based on probabilistic and non-isothermal kinetics. Colour is one of the most widely measured product quality attributes in postharvest handling and in the food processing research and industry. Apart from differences in instrumentation, colour measurements are often reported based on different colour indices even for the same product, making it difficult to compare results in the literature. There is a need for standardisation to improve the traceability and transferability of measurements. The correlation between colour and other sensory quality attributes is well established, but future prospects exist in the application of objective non-destructive colour measurement in predictive modelling of the nutritional quality of fresh and processed food products.

Characterization and evaluation of sensory acceptability of ice creams incorporated with beta-carotene encapsulated in solid lipid microparticles

“…According to Pathare et al (2013), color measurement of food products can be used as an indirect measurement of pigment content and flavor, with the advantage of being also simple and quick to be obtained. Through the values of b*, a*, and L*, shown in Table 3, the values of Chroma (C*ab), Hue angle (H*ab), and total color difference (TCD) were calculated for all formulations, as shown in Figures 2A-C.…”

“…The parameter a* represents the variation of the color from red (positive values) to green (negative values), the parameter b* represents the variation of the color from yellow (positive values) to blue (negative values), and the parameter L* represents luminosity, which varies from black to white (Granato & Masson, 2010;Pathare et al, 2013). All the ice creams tested had positive values of a* and b*, which decreased over the 45 days of storage.…”

“…According to Pathare et al (2013), Chroma (C*ab) is a quantitative attribute of colorfulness, which indicates the color intensity perceived by humans. The values of chroma shown in Figure 2A indicated higher values for IC-4 presented the highest values during the storage period, whereas products with formulation IC-1 presented the lowest.…”

Influence of storage temperature and duration on postharvest physico-chemical and mechanical properties of pomegranate fruit and arils

“…Similarly, three measurements of aril color were taken in a petri dish. The hue angle (h°) was calculated using Pathare, Opara, and Al-Said (2013):…”

Physical and sensory properties of ready to eat apple chips produced by osmo-convective drying

“…The whitening index on the other hand, WI, corresponds to lesser browning and product discoloration and it is an indicator of enzymatic discoloration (Pathare et al 2012a). …”