Analysis of Hydrocolloids in Crystalline Material

Abstract

Additives in foods are a commonly applied tool to optimize the product in terms of appearance, handling, quality, and production process. Such additives are ingredients which can change, e.g., the texture within the product and can also influence other main components in a formulation. It is demonstrated that the use of hydrocolloids as texturants in sweets influences the layer formation of crystallized sucrose for coating purposes. An incorporation of hydrocolloids in the crystalline materials changes the storage stability since the produced coated gels lose water, the so-called syneresis. It is necessary to achieve a pure crystallized sugar layer and, therefore, to develop a tool to control the production process. A successful analysis of hydrocolloids, e.g., of gelatin, agar or carrageenans, in crystallized sucrose was performed by means of precipitation and coloring methods.

Determination of carrageenan in jellies with new methylene blue dye using spectrophotometry, smartphone-based colorimetry and spectrophotometric titration

“…Increased absorbance at long wavelengths beyond the main spectral peak confirms presence of suspended particles (Figure 1c). Similarly, both the MB and TB dyes are known to form fine suspensions with carrageenan (Herfurth & Ulrich 2017;Ziółkowska et al, 2017). The absorbance changes in time are dependent on both carrageenan type and concentration (Figures 2).…”

“…In turn, the differences between carrageenan iota samples from different manufacturers may be due to the presence of hybrid type carrageenans (Campbell & Hotchkiss 2017). Commercial samples of food-grade carrageenan may also contain admixtures of sucrose and dextrose (Herfurth & Ulrich 2017).…”

“…The MB dye form ion associates with anionic polymers resulting in decrease and shift of the main absorbance peak (Coronel et al, 2017;Stîngă et al, 2019). The spectral maximum undergoes hypsochromic shift from 664 nm (blue color) to 559 nm (purple color) (Herfurth & Ulrich, 2017). Absorbance at 664 nm corresponds to monomer form of the dye while absorbance at 559 nm corresponds to dimer form.…”