# Marination of Beef With Unripe Grape (Koruk) Products at Different Holding Times: Quality Assessment

## TL;DR

This study found that marinating beef with unripe grape products and thyme improves its quality, reduces bacteria, and prevents oxidation, especially after 48 hours.

## Contribution

The study introduces unripe grape products as natural marinade components that effectively enhance beef quality and safety.

## Key findings

- Unripe grape products in marinades reduced bacterial counts and oxidation in beef after 48 hours.
- Marinating beef for 24 hours improved sensory properties like color and texture compared to the control.
- UGJ with thyme and salt achieved high overall acceptance scores on a hedonic scale.

## Abstract

The objective of this study was to examine the effects of utilizing unripe grape (koruk) juice (UGJ) and dried unripe grape pomace (DUGP) with thyme as marinade components and applying distinct marination holding times (2, 24, 48 h) on the physical, chemical, microbiological, and sensory properties of beef. pH, total acidity, salt content, water activity, and marinade absorption values of samples were affected by the usage unripe grape products (UGP) in marinade formulations and different marination holding times. UGP demonstrated efficacy in impeding oxidation at 48 h of marinating. The most efficacious treatment in reducing the counts of total mesophilic aerobic bacteria (TMAB) and total psychrotrophic aerobic bacteria (TPAB) in samples was achieved by marination with 50% UGJ for 48 h. The counts of Pseudomonas spp., Enterobacteriaceae, and LAB were below the detection limits for samples marinated with 50% UGJ and 50% UGJ with thyme and salt. If the marination process was conducted for 24 h, it was observed that all marinated sample groups exhibited significantly elevated scores for color, texture, and overall acceptance when compared to the control sample (p < 0.05). The overall acceptance scores of the samples marinated for 24 h with 25% and 50% unripe grape juice, as well as thyme and salt, were 6.6 and 6.7, respectively, on a 9‐point hedonic scale. It was thus concluded that UGJ and DUGP could be recommended as natural components in beef marination for the purpose of improving quality characteristics.

The present study investigated the effects of unripe grape products with thyme and marination times (2, 24, 48 h) on beef properties. Marinating the samples for 48 h showed that grape products prevented oxidation and 50% unripe grape juice was the most effective treatment for reducing TMAB and TPAB counts. It was concluded that unripe grape products can be recommended as natural components in beef marinades to improve their quality.