Effect of conventional and emerging thawing technologies on drip loss, microstructure and post-thaw quality of frozen fruits and vegetables: A review

Abstract

Thawing is an important stage in the handling of frozen foods because it directly influences their safety, nutritional composition, texture and consumer acceptability. The present review provides a comprehensive analysis of both conventional and emerging thawing methods with a special focus on fruits and vegetables. Conventional techniques such as air thawing, water immersion and refrigerated thawing are widely used because they are simple and inexpensive, but they often lead to long thawing times, excessive drip loss, nutrient leakage and microbial safety concerns. Microwave thawing offers faster processing but suffers from uneven heating that can compromise texture and food safety. In recent years, advanced technologies including ultrasound assisted thawing, high pressure thawing, ohmic thawing, radio frequency thawing, infrared thawing and vacuum assisted thawing have attracted significant attention. These methods show promise in reducing drip loss, preserving cellular integrity and maintaining sensory and nutritional quality. However, challenges such as equipment cost, scalability, energy demand and regulatory acceptance continue to restrict their wider adoption in the food industry.

The novelty of this review lies in its detailed comparison of thawing technologies specifically designed for fruits and vegetables, where the preservation of delicate cellular structures and water retention are central to post-thaw quality. Unlike earlier reviews that addressed thawing in general food systems, this paper highlights how different technologies influence microstructure, moisture migration and nutrient stability in plant-based matrices. The analysis further identifies research gaps relating to the limited industrial validation of emerging technologies, the absence of standardised performance criteria and the need for sustainable energy integration. The review also outlines the political, social, and practical implications of adopting these technologies, including consumer acceptance, regulatory frameworks, and potential contributions to reducing food waste.

Overall, the findings suggest that hybrid thawing systems and intelligent process controls hold the greatest promise for achieving efficient, safe and sustainable thawing. By critically assessing both established and novel methods, this paper provides valuable insights to guide researchers, food processors and policymakers in selecting and optimising thawing strategies for fruits and vegetables.