Study on the Composition and In vitro Biological Activity of Strawberry Pineapple Compound Enzyme
Strawberries (Fragaria x ananassa Duch.) are perennial evergreen herbaceous plants in the Rosaceae subfamily, belonging to the genus Fragaria. Their flesh is rich in vitamins and trace elements, and has high nutritional and economic value. The cultivation area and yield are second only to grapes, and pineapple, also known as Ananas comosus (L.) Merr, Belonging to the family Rosaceae and genus Rosaceae, it mainly grows in tropical regions such as South America and is one of the third largest tropical fruits in the world. But they have a high moisture content and are not suitable for storage, so it is extremely important to extend their shelf life through certain techniques.
Enzymes originally originated in Japan, and today the market for enzymes in Japan can reach over 100 billion yen per year. Enzymes are made from one or more fresh vegetables, fruits, mushrooms, Chinese herbs, and other raw materials, mixed with various probiotics for cultivation, and finally fermented into a liquid or solid with specific pharmacological functions. Due to their fermentation products having good antioxidant capacity, macromolecular decomposition ability, and anti-aging effects, they have attracted the attention of many researchers. Fruit enzymes have gradually become a hot topic due to their good biological activity, and the selection of microorganisms is particularly important in fruit and vegetable fermentation, such as yeast, which can improve the nutritional value of food and produce some health regulating substances during the growth process. Therefore, they are highly favored by food producers. Lactic acid bacteria can produce a large amount of organic acids, alcohols, various amino acids and other metabolites during the fermentation process, which have physiological effects such as inhibiting bacterial growth, promoting digestion and absorption, and preventing cancer. The concentration of fruit juice also has a significant impact on the production of acidic substances during fermentation. Studies have shown that when the amount of juice added increases from 30% to 50%, the efficiency of producing acidic substances during fermentation is significantly enhanced. Excessive acidity can cause significant stimulation to the taste buds and oral cavity, while excessively low acidity can affect the pleasure that enzymes bring to people. As an important indicator of enzyme fermentation, acidity can be controlled within a certain range to effectively enhance the flavor of enzymes. Mixing multiple probiotics for fermentation can further improve the taste and flavor of enzymes. Consider using lactic acid bacteria and yeast to ferment together. Yeast fermentation can produce alcohol, which reacts with acid to convert into esters, thereby changing the flavor of the beverage and enhancing its comfort. Therefore, this study used a composite strain of Lactobacillus bulgaricus and fruit wine yeast to ferment strawberries and pineapples, in order to obtain fruit enzymes with higher nutritional value for the human body.
In recent years, enzyme products have become the mainstream of the international market. Currently, enzyme products in China are mainly developed in the Henan area, but the fermentation of single vegetables or fruits dominates the production of enzyme products in China. Enzyme products obtained by fermenting strawberries and pineapples separately have appeared, but I have not yet seen their complex enzymes. Moreover, due to the high content of citric acid and the tendency to cause overheating in fruits, the author suggests mixing different types of fruits instead of using a single fruit. Reasonable combination can comprehensively improve physical condition. Therefore, the development of new and unique pineapple strawberry complex enzyme products has good market prospects. Therefore, this study used a mixture of strawberry and pineapple juice as raw materials, and added yeast and Lactobacillus bulgaricus for fermentation to prepare enzymes. The chemical composition content, functional enzyme activity, antioxidant activity, and antibacterial ability before and after fermentation were preliminarily studied, aiming to improve the added value of strawberries and pineapples and produce a composite enzyme product with higher nutritional value.

This experiment uses a combination of lactic acid bacteria and yeast fermentation to neutralize the acidic and alcoholic substances produced during the fermentation process, resulting in improved taste and flavor of the complex enzyme. After compound fermentation, the total flavonoid content in the strawberry pineapple complex enzyme increased by 1.5 times, and the ability to scavenge hydroxyl radicals and superoxide anion radicals was greatly improved. 10.4% of the strawberry pineapple complex enzyme had a DPPH radical scavenging rate of 58%, which was comparable to the DPPH radical scavenging rate reported by Chen after 30 days of fermentation. 14% of the strawberry pineapple complex enzyme had a high OH scavenging rate of 88%, while Zhao’s reported 56% pineapple enzyme had a OH scavenging rate of only about 60%. Compared with Chen’s highest hydroxyl radical scavenging rate of 76.44% after strawberry enzyme fermentation, the hydroxyl radical scavenging rate of the strawberry pineapple complex enzyme was higher. 20% of the strawberry pineapple enzyme had a higher hydroxyl radical scavenging rate for superoxide anions. The clearance rate of free radicals has reached 100%, while the 70% pineapple enzyme reported by Zhao has a clearance rate of less than 90% for superoxide anion free radicals, And after fermentation, its T-SOD activity nearly doubled and lipase activity significantly increased. The above indicates that strawberry pineapple complex enzyme has better ability to eliminate free radicals compared to strawberry enzyme and pineapple enzyme, and can play a better role in health and beauty. Strawberry pineapple complex enzyme combines the characteristics of both strawberries and pineapples, complementing each other’s strengths and weaknesses, and can comprehensively regulate the user’s body. Therefore, this new type of functional enzyme beverage not only has a certain effect on clearing free radicals and decomposing large molecular substances in the human body, but also has certain promotion and application value in fields such as pharmaceutical research and cosmetics. In addition, it also helps deepen people’s understanding of natural functional foods.