# Improving the Storage Stability of Tomato Paste Enriched by Different Concentrations of Zinc Micronutrient

## TL;DR

This study shows that adding zinc to tomato paste helps preserve its quality and nutritional value during storage.

## Contribution

Zinc fortification is shown to reduce degradation of TPC and AC in tomato paste during storage.

## Key findings

- Zinc-fortified tomato paste showed less degradation of total phenol content and antioxidant capacity compared to the control.
- The Zn-40 ppm group had the smallest reductions in lycopene, TPC, and AC after 60 days of storage.
- Quadratic discriminant analysis accurately identified and distinguished samples across storage periods with 100% accuracy.

## Abstract

This study evaluates the fortification of tomato paste with zinc (Zn) micronutrient and its impact on quality control during storage. Industrial tomato paste was divided into four groups: a control group and three groups fortified with 20 ppm zinc (Zn‐20 ppm), 40 ppm zinc (Zn‐40 ppm), and 60 ppm zinc (Zn‐60 ppm). The samples were stored at 4°C for 60 days, with physical tests: L*, a*, b*, ∆E, and a*/b*, chemical tests: pH, total soluble solids (TSS), lycopene, total phenol content (TPC), and antioxidant capacity (AC), and microbiological tests: acid‐resistant mesophilic bacteria (ARMB) and mold and yeast (MY), assessed every 15 days. Additionally, the aroma properties of the paste were analyzed using an electronic nose system. The results demonstrated a decline in L*, a*, b*, and a*/b* indices and reductions in lycopene, TPC, and AC levels across all treatments during storage. In contrast, ∆E, ARMB, and MY counts increased over time. Lycopene, TPC, and AC exhibited the highest reductions in the control group by the end of storage, at 84.72%, 16.29%, and 38.69%, respectively, while the Zn‐40 ppm group showed the minor decreases, with reductions of 70.85% for lycopene, 3.39% for TPC, and 22.86% for AC. Analysis of variance (ANOVA) indicated that the storage period, fortification levels, and their interactions had significant effects (p ≤ 0.01) on the properties of the tomato paste. The overall accuracy of quadratic discriminant analysis (QDA) in identifying and distinguishing samples across all storage periods was 100%, with no misclassifications among the 32 samples analyzed.

In this research, tomato paste as a high consumption food product has been enriched with zinc micronutrient using certain concentrations. Some of the main results were: Zinc fortification of tomato paste enhances its nutritional value. Zinc‐fortified samples showed less degradation of total phenol content (TPC) and antioxidant capacity (AC). The results of the electronic nose system showed that fortification with Zinc had no significant effect on the smell of tomato paste. Zinc fortification proved beneficial in maintaining product quality over the 60‐day storage period.