Zhao Qin's research while affiliated with Henan University of Technology and other places

Heterocyclic amines (HCAs) have potential carcinogenic and mutagenic activity and are generated in cooked protein‐rich foods. Adding proanthocyanidins (PAs) to these foods before frying is an effective way to reduce HCAs. In this study, polymeric PAs (PPA) and ultrasound‐assisted acid‐catalyzed/catechin nucleophilic depolymerized PAs (UAPA, a type of oligomeric PA) were prepared from Chinese quince fruits (CQF). Different levels of PPA and UAPA (0.05%, 0.1%, and 0.15%) were added to chicken meatballs and tofu; then these foods were fried, and the content of HCAs in them after frying was investigated. The results showed that PPA and, particularly, UAPA significantly inhibited the formation of HCAs in fried meatballs and tofu, and this inhibition was dose‐dependent. The inhibition of HCAs by both PPA and UAPA was stronger in the chicken meatballs than in fried tofu. The level of total HCAs was significantly reduced by 57.84% (from 11.93 to 5.03 ng/g) after treatment of meatballs with 0.15% UAPA, with inhibition rates of 78.94%, 50.37%, and 17.81% for norharman, harman, and 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), respectively. Of note, there was a negative correlation between water, lipid, protein, creatine, and glucose content and HCA content in the crust, interior, and whole (crust‐plus‐interior) measurements of all fried samples. Interestingly, PPA and UAPA were found more effective in inhibiting HCAs in the exterior crust than in the interior of the fried chicken meatballs. These results provide evidence that further studies on the reduction of the formation of harmful HCAs in fried foods by adding CQF PAs could be valuable to the fried food industry. Practical Application Chinese quince proanthocyanidins treatments significantly inhibited the generation of heterocyclic amines (HCAs) in chicken meatballs and tofu when deep‐fried. These results suggest that Chinese quince proanthocyanidins can be used as natural food additive for reducing HCAs in fried foods, laying the foundation for using Chinese quince fruit proanthocyanidins for HCA inhibition in the food industry.

The abilities of Chinese quince free proanthocyanidins (FP) and bound proanthocyanidins (BP) at different levels (0.1%, 0.15%, and 0.3%) to mitigate heterocyclic aromatic amine (HAA) formation in fried chicken patties were investigated for the first time and compared with vitamin C (Vc). FP and BP reduced HAAs in a dose‐dependent manner. Significantly, high concentrations of FP (0.3%) resulted in a reduction of PhIP, harman, and norharman levels by 59.84%, 22.91%, and 38.21%, respectively, in chicken patties. The addition of proanthocyanidins significantly ( p < 0.05) reduced the weight loss of fried chicken patties. Furthermore, a positive correlation was observed among pH, weight loss, and total HAA formation in all three groups (FP, BP, and Vc). Multivariate analysis showed that FP had a more pronounced effect than BP from the perspective of enhancing the quality of fried chicken patties and reducing the formation of HAAs. These results indicate that proanthocyanidins, both BP and FP, but especially FP, from Chinese quince can inhibit the formation of carcinogenic HAAs when added to protein‐rich foods that are subsequently fried.

This study analyzed the chemical composition and antioxidant properties of proanthocyanidins (PAs) in Chinese quince fruits at six growth stages. UPLC-QTOF-ESI-MS/MS and MALDI-TOF-MS identified and quantified the chemical composition, while radical scavenging ability assessed antioxidant capacities. PA concentration peaked during mid-growth and declined as fruits ripened. The highest total proanthocyanidin content occurred in August (1776.69 ± 56.97 mg PB2/100 g FW). Catechin and epicatechin were the primary PA subunits, forming trimers to tetradecamers and higher degrees of PAs. The PA extracts were composed predominantly of highly polymerized B-type procyanidins with degrees of polymerization (DP) greater than 4, which accounted for over 93% of total PA content, along with minor amounts of dimeric and trimeric prodelphinidins. Molecular weight of PA samples decreased as fruits ripened. The highest antioxidant activities against DPPH⁺• and ABTS⁺• were observed in July (IC50 = 7.17 ± 0.073 µg/mL) and August (IC50 = 67.47 ± 2.29 mg/mL), respectively, with the highest FRAP activity in July. Immature fruits with elevated PA content and antioxidant capacity show promising potential for functional food applications. Graphical abstract