Kinetics of the thermal degradation of lycopene in tomatoes

Abstract

This research studied the kinetics of the thermal degradation of lycopene in tomatoes using elevated temperature testing. Understanding the nature and the extent of sensitive nutrient degradation in tomatoes will assist in reducing postharvest nutrient losses during storage and processing. Ripe tomatoes were sorted, washed, and blinded. Juice was obtained by filtering the blinded pulp through a muslin cloth. The samples were heated using a water bath at 70, 80, 90, and 100 °C for 20, 40, 60, and 80 minutes. The determination of lycopene was done using spectrophotometric methods at 503 nm, in hexane: ethanol: acetone (2:1:1 v/v/v) lycopene extract. The concentrations of lycopene were determined immediately after processing. The data was found to fit into first order equations. Degradation constants (k), D-value, and half-life for the thermal degradation of lycopene were determined at each processing temperature. Models were also developed for each of the chosen temperatures, which can be used to predict the degradation pattern of lycopene at other processing conditions. Z-value, Q10, and activation energy for the degradation of lycopene were also determined. Analyses showed a considerable decrease in lycopene concentration and decimal reduction time (D-value), and a significant increase in the thermal degradation rate (k) during heating from 70 to 100 °C. The finding shows that the degradation of lycopene in tomatoes followed the first order kinetics and it shows that the lycopene content decreased at 80 to 100 °C.

Promising self-emulsifying drug delivery system loaded with lycopene from red guava (Psidium guajava L.): in vivo toxicity, biodistribution and cytotoxicity on DU-145 prostate cancer cells

“…Temperature is one of the main factors that affect lycopene stability. High temperatures induce isomerization, followed by autooxidation of unsaturated bonds, which hinders further biological applications (Srivastava and Srivastava 2015;Aliyu et al 2020). Our findings indicate that the nanoemulsion preserves lycopene integrity for months under refrigeration, allowing their biotechnological application.…”

Influence of Pasteurisation (Conventional vs. Radiofrequency) and Chill Storage on Retention of Ascorbic Acid, Tocopherol and Carotenoids in Salmorejo

“…Lycopene is stable in tomato products heated at 80-100 • C, while its isomerisation increased at 120-140 • C, resulting in a degradation of total lycopene and cis-isomers [18]. Lycopene degrades following a first order kinetic in the tomato juice heated at 80 to 100 • C for 20 to 80 min [19]. In crushed tomato, lycopene content (3.5 mg 100 g −1 ) decreased by up to 55% after heating at 100 • C for 120 min [17].…”

Physicochemical and sensorial properties of tomato leathers at different drying conditions

“…Hexane was used as the blank. The amount of lycopene was calculated by using the following equation (Aliyu et al., 2020): $$$$\begin{equation} \mathrm{lycopene}\, \left(\mathrm{mg}/\mathrm{kg}\, \mathrm{fresh}\, \mathrm{wt}.\right)={\mathrm{A}}_{503}\ensuremath{\times{}}171.7/W, \end{equation}$$$$where W is the weight of the sample (g), and A is the absorbance at 503 nm. 171.7 mM −1 is the extinction coefficient for lycopene in hexane (Zechmeistbr et al., 1943).…”