Influence of cold plasma treatment on triacylglycerol polymorphism and crystalline structure in chocolate

Chocolate pre-crystallization is a critical step that determines the final structural and quality attributes of chocolate through the formation of stable cocoa butter crystal networks. Inefficiencies in this traditional pre-crystallization stage often lead to inadequate tempering, resulting in significant food waste due to quality defects like fat bloom and poor texture. Here, we evaluate cold plasma (CP) as a potential alternative for chocolate pre-crystallization, offering a method to facilitate the development of stable crystal formation under ambient processing conditions. Our findings indicate that CP treatment produced structural and thermal features consistent with stable β-type crystals (β 2 /β 1 region) across milk, dark, and white chocolates, with β 2 (Form V) inferred indirectly from combined XRD, DSC, and temper-index (5.0–5.5 CTU) evidence rather than directly resolved, because β 2 and β 1 share nearly identical short-spacing reflections that XRD alone cannot discriminate; this assignment was not independently confirmed. XRD and FTIR analyses indicated that CP-treated samples showed crystalline organization comparable to commercial products, but through a process operating at near-ambient temperatures. DSC showed single, well-defined melting peaks within the β 2 /β 1 melting range. Overall, the results indicate that CP-assisted pre-crystallization can produce structural and thermal characteristics comparable to those of commercial chocolate samples, providing a basis for further investigation of CP as an alternative pre-crystallization approach.