Abstract
Background: Moringa is a tree which not a well-understood plant since it has not been entirely studied all over the world. Fruit Juice however, especially guava (Psidium guajava L) juice is very desirable for the consumer because of its fresh aroma and delicious flavor, but its shelf life is less than 6 days at 4 +/- 1 degrees C. Therefore, the aim of the present study is to evaluate the chemical and biological properties of the Moringa oleifera leaves aqueous extract (M.O.A.E) as a natural preservative of fresh juices and to produce untraditional healthy products as well as prolong the shelf life. This study treated Fresh Guava Whey Juice (F.G.W.J) by 1.5 and 2.0% of (M.O.A.E), respectively. Results Proximate analysis ascertained that M.O.A.E is a vast source of vitamin C (156.26mg/100g), antioxidant activity (85.44%), and phenolic compounds (55.6 mg GAE/gm), respectively. Total phenolic compounds in F.G.W.J (control sample) reached to 50.5%, while the fortified beverage with 1.5 and 2.0% M.O.A.E, reached 64.8 and 76.3% respectively at zero time of storage. Both control and fortified samples of F.G.W.J with M.O.A.E (1.5 and 2.0%) showed a higher scavenging activity by 80.28 %, 93.39 and 98.39%, respectively after 2 months of storage. Results also indicated that M.O.A.E may be used as an antimicrobial agent with reasonable safety margins to inhibit bacterial growth in pharmaceutical and food applications. It appeared that using HPLC hydrolysis method is the most suitable process for the extraction of phenolic compounds from pure M.O.A.E and F.G.W.J fortified with M.O.A.E. Conclusion: It is concluded that it was applicable, successful and accessible to utilize moringa crop in producing many edible and preferable manufactured products. lastly, the fortification of F.G.W.J with 1.5 or 2% were the exact ratios for using M.O.A.E in such juice to prolong shelf life.