## 4 Impacts of HTST and UHT on Food Quality
### Bioactive Compounds
#### 4.3.2. Phenolics
Also, further condensation of breakdown products with organic acids or carbohydrates can cause a decrease in the contents of these bioactive components [27; 37; 39; 83; 84]. In pomegranate juice there was a 29.3% decrease in TPC [70], and in mulberry juice there was a decrease of less than 4% [27]. Some researchers state that the anthocyanin content decreased during storage by 75.3% after 25 days of storage at 4 \({}^{\circ}\)C in pepper and orange juice blend [42] and by 7.8% and 34.1% during 12 weeks of storage of purple sweet potato nectar at 4 \({}^{\circ}\)C and 25 \({}^{\circ}\)C, respectively [35]. The HTST technique can perform significant extraction of phenolics from a raw food matrix. In sea blackthorn juice, there was a 6.6% increase in TPC following preservation at 100 \({}^{\circ}\)C for 15 s due to cell disruption [56]. In peach juice, preservation by HTST resulted in an increase from 617.2 mg (raw juice) to 1000.3 mg GAE/L (72 \({}^{\circ}\)C/15 s). An upward trend was also shown during storage (by 11.4% over 28 days) but to a significantly lesser extent than in raw juice (by 140.3% over 28 days) [31]. In addition, an increase in TPC content was also shown by [PERSON] et al. [57]. Also, studies have been described in which phenolics are largely degraded [5] or only slightly, like in lemonade and citrus juice by 3.6% and 7.6%, respectively [64]. [PERSON] et al. [82] observed, after the HTST process, a decrease in the phenolic acids content of less than 3%, and, on the other hand, an increase in flavonoids of 61.5%. Nonsignificant changes in TPC and total ellagitannin content in an HTST-preserved (71.1 \({}^{\circ}\)C/3 s) blackberry-soy-flaxseed beverage were observed by \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Matrix** & **Parameters** & **Phenolic Compounds** & **Vitamins** & **Other Bioactive Ingredients** & **Reference** \\ \hline \multirow{8}{*}{Freshly squeezed lettuce juice} & \multirow{8}{*}{115 \({}^{\circ}\)C/5 s} & Vitamin C8.1\% \(\downarrow\) & \multirow{8}{*}{Total chlorophyll 14.1\% \(\downarrow\) *} \\  & & & Vitamin K1 442 \(\downarrow\) * & Chlorophyll 13 13.7\% \(\downarrow\) * \\  & & & Vitamin B1 25 \(\downarrow\) * & Chlorophyll 1 & 13.7\% \(\downarrow\) * \\  & & & Vitamin B2 4.7\% \(\uparrow\) & Vitamin B1 4.9\% \(\downarrow\) * \\  & & & Vitamin B3 22 \(\downarrow\) * & Total \(\beta\)-carotene 35.7\% \(\downarrow\) * \\  & & & Vitamin B6 2.7\% \(\downarrow\) * & (all E)-\(\beta\)-carotene 44.2\% \(\downarrow\) * \\  & & & Vitamin B9 31.7\% \(\downarrow\) * & (\(\beta\))-\(\beta\)-carotene 182.7\% \(\uparrow\) * \\  & & & Vitamin B12 12.3\% \(\downarrow\) * & \\ \hline Mulberry juice & 110 \({}^{\circ}\)C/8.6 s & Total anthocyanin content 3.6\% \(\downarrow\) * & - & - & [55] \\ \hline \hline \end{tabular}  
* \(\uparrow\)—Increase; \(\downarrow\)—decrease.
* Statistically significant change. TPC—total phenolic content; TPC—total flavonoid content; TCC—total carotenoid content.  
\end{table} 
Table 2: _Cont._[PERSON] et al. [67]. A significant decrease of 27.5% in total monomeric anthocyanins content was shown by [PERSON] et al. [70]. Despite the differences in the preservations of phenolics, their degradation occurred during prolonged storage as a result of heating in different food matrices and using different parameters [88]. A different conclusion was reached by [PERSON] et al. [82], who noted increases in phenolic acids and decreases in the flavonoid contents in an HTST-preserved fruit-juice-soymilk beverage during 56 days of storage. [PERSON] et al. [5] showed a relatively stable TPC during storage (Table 3). No significant effect of HTST on anthocyanins was observed by [PERSON] et al. [57] in pomergnate-lemon juice and pomergnate juice because of the short processing time (90 \({}^{\circ}\)C/5 s). In addition, a decrease in anthocyanin content of 27.6% was reported by [PERSON] et al. [70].