Impact of thyme oil enrichment and drying on microstructure and physicochemical quality of pumpkin snacks: A fractal analysis approach

IF 7.1 3区农林科学 Q1 FOOD SCIENCE & TECHNOLOGY

Food Structure-Netherlands Pub Date : 2026-04-01 Epub Date: 2026-05-16 DOI:10.1016/j.foostr.2026.100529

Ana Divito , Ma. Roberta Ansorena , Rosario Goyeneche , Nicolás Villagrán dos Santos , Guido Rolandelli , Cristina dos Santos Ferreira , Cintia Mazzucotelli , Pilar Buera , Karina Di Scala

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引用次数: 0

Abstract

The global market for dehydrated vegetable-based snacks has expanded significantly, driven by consumer preferences toward natural healthy products. This study explores convective dehydration (50–70 °C) not only as a preservation technique but also as a platform for developing functionally enriched pumpkin snacks (Cucurbita moschata) containing free and microencapsulated thyme essential oil. The snacks microstructure was characterized through an integrated imaging approach, including Scanning Electron and Confocal Laser Scanning Microscopy together with and Fractal analysis. Thermodynamic stability was evaluated analyzing water sorption isotherms and glass transition temperature. Results identified 70 °C as the optimal drying temperature, yielding the highest total polyphenol content (196.33 ± 16.16 mg GAE/100 g db) and antioxidant capacity (15.35 ± 0.94 mg TE/100 g db) while simultaneously optimizing sensory acceptability and process time (170 min.). Samples containing microencapsulated oil exhibited higher fractal dimensions (ranging from 1.810 to 1.840) and lower lacunarity values (decreasing from 0.4785 to 0.3012) at magnifications of 1000x and 5000x, respectively. These samples presented a reduced W-parameter from the GDW water sorption model showing a fundamental modification in water-matrix interactions. Microencapsulated enriched samples exhibited superior thermal stability, reflected by higher Tg values (e.g. 29.33 °C at 20% H₂O). Antioxidant capacity of these samples highlighted their protective role on bioactive compounds (DPPH: 64.57 mg TE/100 g db) compared to free oil impregnated samples. These findings underscore the synergy between microscopy together with fractal image analysis as a robust framework for the design of innovative microencapsulated-oil plant-based snacks with tailored functional and structural properties.

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百里香油富集和干燥对南瓜零食微观结构和理化品质的影响：分形分析方法

由于消费者对天然健康产品的偏好，脱水蔬菜零食的全球市场已经显著扩大。本研究探讨了对流脱水（50-70°C）不仅是一种保存技术，而且是开发含有游离和微胶囊化百里香精油的功能丰富的南瓜零食（Cucurbita moschata）的平台。通过扫描电子显微镜、激光共聚焦显微镜和分形分析等综合成像方法对零食的微观结构进行了表征。通过分析吸附等温线和玻璃化转变温度来评价其热力学稳定性。结果发现70°C的最佳干燥温度、收益率最高的总多酚含量(196.33 ±16.16 GAE 毫克/ 100 g db)和抗氧化能力(15.35 ±0.94  mg TE / 100 g db)同时优化感官接受和处理时间(170 分钟)。在1000倍和5000倍的放大倍数下，微胶囊化油样品的分形维数较高（1.810 ~ 1.840），空隙度值较低（0.4785 ~ 0.3012）。这些样品呈现出来自GDW吸水模型的减小的w参数，表明水-基质相互作用的基本修改。微囊化富集样品表现出优异的热稳定性，反映在较高的Tg值上（例如，在20% H2O下29.33°C）。与游离油浸渍样品相比，这些样品的抗氧化能力突出了它们对生物活性化合物的保护作用（DPPH: 64.57 mg TE/100 g db）。这些发现强调了显微镜与分形图像分析之间的协同作用，作为设计具有定制功能和结构特性的创新微胶囊油植物零食的强大框架。

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来源期刊

Food Structure-Netherlands Chemical Engineering-Bioengineering

CiteScore

7.20

自引率

0.00%

发文量

期刊介绍： Food Structure is the premier international forum devoted to the publication of high-quality original research on food structure. The focus of this journal is on food structure in the context of its relationship with molecular composition, processing and macroscopic properties (e.g., shelf stability, sensory properties, etc.). Manuscripts that only report qualitative findings and micrographs and that lack sound hypothesis-driven, quantitative structure-function research are not accepted. Significance of the research findings for the food science community and/or industry must also be highlighted.