Impact of formulation and processing conditions on the material properties and sensory characteristics of confectionary products and model systems across the stages of sugar cooking

Obas, Frantz-Lairy

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https://hdl.handle.net/2142/120519 Copy

Description

Title

Impact of formulation and processing conditions on the material properties and sensory characteristics of confectionary products and model systems across the stages of sugar cooking

Author(s)

Obas, Frantz-Lairy

Issue Date

2023-04-24

Director of Research (if dissertation) or Advisor (if thesis)

Schmidt, Shelly J

Doctoral Committee Chair(s)

Lee, Soo-Yeun

Committee Member(s)

• Lee, Youngsoo
• Cadwallader, Keith R
• Schwenk, Michelle
• Thomas, Leonard C

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Sugar cooking, High-solids gels, Napping-UFP, Gelatin, Triple-Helix, Helix-coil,

Abstract

The stages of sugar cooking have been widely used in the confectionary industry as a practical tool to produce all types of confections, which exhibit a wide range of physical and textural properties. The glass transition temperature (Tg) is an important parameter affecting processing conditions, product properties, and stability of a wide range of confections. However, the glass transition temperatures associated with the stages of sugar cooking and the extent of thermal decomposition induced by the cooking process remain a gap in the literature, calling for further exploration. To bridge this gap, the overall goal of this research was to integrate Tg into the stages of sugar cooking, so as to further strengthen their scientific foundation and increase their value as a practical, science-based tool for producing and controlling the stability and textural properties of all type of confections. A real-world sampling of the changes in the glass transition, both within and across the stages of sugar cooking was obtained by characterizing the thermal behavior and physical properties of currently available, representative commercial confections within each stage of sugar cooking using differential scanning calorimetry (DSC), moisture content and water activity measurements, respectively. The rubbery amorphous products exhibited a much wider variation in their moisture content and glass transition temperature values compared to the glassy amorphous products. The glass transition temperature generally increased with the stages of sugar cooking but there were exceptions, which underscored the significant role that formulation, specifically sweeteners type and ratios, play in determining the thermal behavior of confectionery products. The commercial confections characterization results opened the door to the development of sugar-based model systems assessing the effect of the type (DE and form) of sweeteners (42 DE corn syrup liquid, 42 DE corn syrup solids, 63 DE corn syrup) and ratios (50:50 or 70:30 sucrose to corn syrup) on the thermal behavior and compositional changes due to thermal decomposition across the stages of sugar cooking, using DSC and high-performance liquid chromatography (HPLC), respectively. Ranges of moisture content and Tg values associated with each stage of sugar cooking were developed. In general, model systems made with 63 DE corn syrup have lower Tg midpoint and higher amount of thermal decomposition compounds than model systems made with 42 DE corn syrup. There was significant interaction between the ratio of sucrose to corn syrup and the types of corn syrup (42 DE liquid, 42 DE solid, and 63 DE liquid) on their effect on Tg. The fingerprinting of the composition of the model systems through HPLC revealed that the thermal treatment caused significant changes in the composition of the model systems, mainly observed as an increase in the maltose and glucose content, as well as the formation of fructose and 5-HMF beginning at the soft crack stage. It was found that the dextrose equivalence (DE) of the corn syrup had the strongest effect on both the Tg and thermal decomposition. One particular group of confections within the soft ball stage of sugar cooking, high solids gels, were investigated in depth due to their intriguing thermal behavior and their widespread use in the confectionary and dietary supplement industries use as delivery systems for vitamins, mineral, and other bioactive compounds. Thus, moisture content analysis, DSC, texture profile analysis, and Napping Ultra Flash Profile (Napping-UFP) were used to unravel the connection across the physical, thermal, textural properties, and sensory characteristics of 13 commercial HSGs. Hierarchical clustering of the Napping-UFP data set for global and texture attributes resulted in the identification of two categories of HSGs: Gelatin containing and non-gelatin containing products. The difference in texture between the two clusters, as evaluated by the sensory panelists, was associated with the presence of a small (3 J/g) gelatin triple-helix structure determined by DSC. The Napping-UFP results have established that gelatin triple-helix is a powerful structural element influencing the textural properties of gelatin HSGs. Given the stark difference in texture between gelatin containing and non-gelatin containing HSGs, the final phase of this research aimed to identify the thermal and structural characteristics of gelatin in a commercial HSG, as well as to determine the effect of time and temperature on the renaturation and loss of gelatin helical structure. DSC, powder X-ray diffraction (PRXD), and total scattering pair distribution function (TSPDF), were used for all the experiments. The gelatin HSG is in the amorphous rubbery state at room temperature (20-25°C) with Tg onset, midpoint, endpoint and ΔCp of ‑34.50 ± 0.52, ‑27.00 ± 0.40, ‑19.6 ± 0.41 °C, and 0.724 ± 0.007 J/ (g °C), respectively. The thermal (DSC) and structural (PRXD and TSPDF) characterization results showed that the helix-coil transition in the gelatin HSG is characteristic of a thermal denaturation event, not a melting event, as no crystalline structure was present in the gelatin HSG. The onset and peak temperatures of the helix-coil transition of the gelatin HSG increased with renaturation temperature (at ‑4 to 36°C for 24h), whereas the amount of triple-helix structure reformed increased with renaturation temperature up to 22°C, then decreased. Both the loss and renaturation of gelatin helical structure were time dependent. The gelatin HSG helix-coil transition parameters (Td onset, Td peak, and enthalpy) depend on the imposed thermal history, specifically renaturation temperature and time. Further, these results should support the potential development of gelatin HSG with increased thermal stability and textural properties. The technical challenges of replacing gelatin in HSG systems will be overcome more effectively through the improved understanding of the thermal and structural characteristics of gelatin studied herein. This thorough characterization of gelatin HSG will assist in identifying materials that exhibit similar features as gelatin.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Frantz-Lairy Obas

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