A recent study conducted by Prof. Yukiharu Ogawa and Jutalak Suwannachot from Chiba University explored the changes in phenolic compounds and antioxidant activity in Shiso-zuke Umeboshi, a traditional Japanese apricot pickle pickled with red perilla leaves. The research focused on evaluating the qualitative and quantitative alterations in the phenolic profiles and antioxidant levels during the production of these pickles and simulated in vitro digestion. The study revealed significant increases in phenolic content during the processing stages, suggesting a gradual rise in antioxidant activity throughout the digestion process, supporting the health benefits associated with this pickling method.
Japanese apricot fruits possess a diverse biochemical composition that contributes to their various health benefits, including anti-inflammatory, antioxidant, and antimicrobial properties due to their high levels of key phenolic compounds and hydroxycinnamic acids. The study aimed to provide essential insights into the potential health benefits of apricot pickled with red perilla, known as Shiso-zuke Umeboshi. The research team utilized various pickling methods to produce perilla-pickled apricots and evaluated the phenolic composition and antioxidant activity using advanced techniques.
The results of the study indicated that the pickling process with red perilla leaves led to a gradual increase in various bioactive compounds, with rosmarinic acid identified as the predominant phenolic compound in all samples. Ferulic acid, caffeic acid, and p-coumaric acid were also detected in different concentrations, with higher levels observed in the finished product (PP) compared to the 30-day pickling stage (30-PP). The researchers utilized liquid chromatography-mass spectrometry to analyze the phenolic fractions and determine their antioxidant potential throughout the processing and digestion stages.
Simulated in vitro digestion was conducted to mimic the gastrointestinal process and evaluate the release of bioactive compounds during different digestion stages. The study showed that the highest release of bioactive compounds occurred before digestion, with a significant increase observed during the small intestinal digestion stage. The antioxidant activity of the pickle samples was higher in PP compared to salt pickling (SP) throughout the digestion process, indicating that the acidic conditions during pickling enhanced the availability of antioxidant compounds, particularly rosmarinic acid and other perilla constituents.
Overall, the findings of the study suggest that the health benefits of Japanese apricot pickles, specifically Shiso-zuke Umeboshi pickled with red perilla leaves, are mainly attributed to the antioxidant compounds present in red perilla. The research highlights the potential of these pickles as functional foods that provide essential nutrients and health benefits beyond traditional micronutrients. The study underscores the importance of further research to explore the specific effects of apricot pickled with red perilla and to enhance our understanding of the potential health-promoting properties of this traditional Japanese pickle.