Examining the effect of jerusalem thorn (Paliurus spina-shristi Mill.), oriental hackberry (Celtis tournefortii L.) and black seed (Nigella sativa L.) on N(epsilon)-(carboxymethyl) lysine formation, sensory, microbial quality in meatballs

This study was conducted to examine the effect of Jerusalem Thorn (Paliurus spina-christi Mill./PSC) and Oriental hackberry tree (Celtis tournefortii L./CT) fruits and black cumin (Nigella Sativa L./NS) seed on the microbial and sensory quality during the storage of meatballs containing tail and beef kidney fat at +4oC and on the formation of Nε–(carboxymethyl)lysine (CML) when cooked at different temperatures. PSC and CT fruits and NS seed were found to contain total phenolic and flavonoid contents, 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, phenolic and volatile compounds before adding them to the meatballs. Experimental groups were formed by adding 2% PSC and CT fruits and NS seed to the meatballs. Prepared meatball samples were covered with stretch film in polyethylene plates and stored at 4±1°C for 16 days, and analyses were performed at four-day intervals throughout the storage period. By using tail and kidney fat, the meatballs were sensorially examined in terms of color, odor, flavor, texture and appearance as well as chemically in terms of CML, thiobarbituric acid reactive substances (TBARS), pH, water activity (aw) and cooking loss. Also, the effect of PSC, CT and NS on microbial quality in meatballs was identified. PSC and CT fruits and NS seed used in the meatball composition were rich in phenolic and volatile compounds and had antioxidant properties. The highest phenolic substance amount and antioxidant activity were found in PSC fruit. The aw values of the meatball groups used in sensory and chemical analyses were 0.931-0.951 on day 0 and 0.963-0.985 on day 16, and their pH values were 5.66-6.06 on day 0 and 6.10-6.74 on day 16. It was observed that there was a decrease in aw and pH values on day 4, but an increase in the other storage days during the storage period in all groups. The cooking loss values of the meatballs were between 22.18-30.23% on day 0 and between 20.89-29.82% on the day 16. The TBARS values of the meatballs were 1.17-1.98 on day 0 and 1.70-3.34 mg MDA/kg on day 16. On days 12 and 16 of the storage period, difference was observed between the TBARS values of the control groups and of the PSC, CT and NS groups, which they changed by 0.13-0.90, 0.40-1.30, 0.50-1.20 mg MDA/kg, respectively. The CML amounts of the meatballs were 11.15-13.45 on day 0 and 13.43-18.17 μg/g on day 16. On days 12 and 16 of the storage period, differences were observed between the control groups and the PSC, CT and NS groups with varying ratios as follows: 1.96-3.36, 1.69-3.55, 1.58-3.65 μg/g, respectively on day 12 and 1.71-4.25, 1.98-4.74, 1.59-4.32 μg/g, respectively on day 16. As a result of the sensory analyses, it was determined that the texture of the meatballs was negatively affected by the addition of PSC fruit, and their appearance by the addition of NS seed. Meatball groups with added CT fruit showed the most positive effect in terms of flavor. NS seed affected the a* value of the meatballs negatively, and the cooking process caused a decrease in the L*, a* and b* values of the meatballs. The highest a* value was found in meatballs with added CT fruit. TMAB, psychrotrophic, LAB and yeast-mold counts of meatball samples were 5.14-5.53, 4.62-4.83, 5.04-5.32 and 3.40-3.87 log10 cfu/g, respectively on day 0, and 7.01-7.9, 7.64-8.24, 7.59-8.05 and 5.69-6.27 log10 cfu/g, respectively on day 16. PSC and CT fruits and NS seed slowed down the microbial growth rate in meatballs. The best antimicrobial effect was found in psychrotrophic bacteria for CT fruit and in LAB and yeast-mold for NS seed. In conclusion, it can be emphasized that the addition of PSC and CT fruits and NS seed, which have polyphenol content, antimicrobial and antioxidant properties to meatballs, they can be gain a functional properties and turn into a more beneficial product in terms of human health.