Nguyen Phuoc Minh et al /J. Pharm. Sci. & Res. Vol. 11(4), 2019, 1451-1454 Different Parameters of Herbal Tea Production from Straw Berry (Muntingia calabura) Leaf Nguyen Phuoc Minh1,*, Nguyen Phu Thuong Nhan2, Nguyen Ngoc Anh Khoa3, Nguyen Ngoc Thao4, Nguyen Thi Tram5, Vo Phu Sang6 1Faculty of Chemical Engineering and Food Technology, Nguyen Tat Thanh University, Ho Chi Minh, Vietnam 2NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam 3Can Tho University, Can Tho City, Vietnam 4Vinh Long Education Technology, Vinh Long Province, Vietnam 5Ho Chi Minh University of Technology, Ho Chi Minh City, Vietnam 6Kien Giang University, Kien Giang Province, Vietnam Abstract. Muntingia calabura is an underexploited fruit in South of Vietnam. Muntingia calabura L is a fast growing medicinal plant, attracts fruit eating birds such as flower peckers. It is a sweet fruit and mainly used as fresh fruit consumption. Muntingia calabura fruit is rich in antioxidant polyphenol and possess significant antioxidant activity, is an important and interesting finding. Straw berry leaves (Muntingia calabura) contain antioxidants that generally form by phenolic or pholifenols, the sinamat acid derivatives, flavonoids, tocopherols, coumarin and polifungsional acids. Flavonoids that have an antioxidant activity consist of flavonol, flavanon, flavones, isoflavones, catechins and kalkon. There is limited study mentioning to processing of this phytochemical leaf. Therefore we explored a herbal tea production from this leaf by focusing on the effect of different parameters such as the effect of blanching temperature and time; heat pump drying temperature and storage condition to vitamin C (mg/100g), flavonoid (mg/g) and sensory score of the dried Muntingia calabura leaf tea. Results showed that o Muntingia calabura leaves should be blanched in hot water 95 C at 5 seconds in the present of CaCl2 0.5% and then beeing dried by heat pump dryer at 40oC until 8% moisture. The final herbal tea could be preserved under vacuum in PET/AL/PE bag at 4oC to maintain flavonoid content for 12 months. Keywords: Muntingia calabura, blanching, drying, heat pump, herbal tea, vacuum 1. INTRODUCTION components of the essential oils can also undergo Drying is the most common method of medicinal plant transformation as a result of resinification. The dried preservation and, due to high investment and energy costs, product is also a favourite habitat for certain insects. drying is also a large expense in medicinal plant Straw berry (Muntingia calabura) belonging to production. Drug quality and consequently earnings are Elaeocarpaceae family. This plant is a fast-growing tree of significantly influenced by the drying regime. Heat slender proportions, reaching a height of approximately sensitive properties (aromatic, medicinal, culinary, colour) 7.5–12 m with nearly horizontal spreading branches. It is provide specialty crops with their high market value. Care often seen growing as roadside trees (Ragragio EM et al., must be taken when drying specialty crops not to cause 2014), also used as an air pollution tolerance indicator. It is extreme losses of heat sensitive properties. Therefore, they an annual plant, flowers throughout the year. M. calabura must be dried at low temperatures for longer periods of are evergreen approximately 5–12.5 cm long, alternate time resulting in large power requirements for dryer lanceolate or oblong, long pointed at the apex, oblique at operation. Heat pumps can simultaneously raise the the base with dark green color and minutely hairy on the temperature from that of the waste heat stream and multiply upper surface, gray- or brown-hairy on the underside and the energy supplied to the heat pump. Pereira et al. (2004) irregularly toothed. The leaves are rich in flavanoidal justified the addition of a heat pump system to a convention compounds like flavones, flavanones, flavans, and re-circulating convection dryer. They found that heat biflavans as the major constituents, possessing antidiabetic pumps are able to deliver more energy than they consume. and cytotoxic activities (Perez GRM et al., 1998; Nshimo It was stated that the additional compressor energy required CM et al., 1993). Straw cherry (Muntingia calabura) leaf is counterbalanced by the energy savings if traditional extract contains flavanoid compounds, terpenoids, tannins (fossil fuel or electrical resistance) dryers were used and high antioxidant activity (Diana Triswaningsih et al., instead. Chua et al. (2002) discusses advantages and 2017). Its leaves are distinctively lanceolate in shape, with limitations of heat pump dryers as compared with margins irregularly serrate and fruits are berries which turn conventional convection dryers. Increased efficiency, red on maturation and are sweet in taste (Bayer C et al., accurate control of drying conditions, wide range of drying 1998). The fruits are abundant, in round shape; conditions, better product quality, increased throughput, approximately 1–1.25 cm wide, with red or yellow, thin, and reduced operational cost all provide a distinct smooth, tender skin and light-brown, soft, juicy pulp, with advantage to heat pump dryers. Freshly dried herbs are very very sweet, musky, fig-like flavor, and filled with storage-sensitive products. Microbiological deterioration exceedingly tiny, yellowish seeds (N. D. Mahmood et al., caused by fungal agents can also occur within a short time. 2014). Phytochemical studies revealed that it presented Loss of active ingredients is a major problem encountered phenolics, flavonoids, terpenoids, reducing sugars, in stored herbs. These involve various reactions. Certain saponins, tannins, and carbohydrates, anthocyanins, 1451 Nguyen Phuoc Minh et al /J. Pharm. Sci. & Res. Vol. 11(4), 2019, 1451-1454 ascorbic acid and vitamin E. (Preethi Kathirvel, 2017; 2.2.2 Effect of drying temperature to vitamin C Vijayanand S and Ann Steffy Thomas, 2018). Their fruits (mg/100g), flavonoid (mg/g) and color (sensory score) in are processed in to jams, leaves are used for making tea. the dried Muntingia calabura leaf tea Fruit from Muntingia is also harvested for export overseas Raw Muntingia calabura leaves were blanched in water o (Marimuthu Krishnaveni and Ravi Dhanalakshmi, 2014). solution with 0.5% CaCl2 at 95 C in 5 seconds. Then these Reports are there for its anti-tumor, antinociceptive, anti- samples would be dried under heat pump dryer at different inflammatory, anti-pyretic, antibacterial, antiproliferative temperature (35oC, 40oC, 45oC, 50oC, 55oC, 60oC) until 8% and antioxidant, antihypertensive, antiulcer and moisture. All samples were analyzed vitamin C (mg/100g), antistaphyloccocal activities (Kaneda NJM et al., 1991; Su flavonoid (mg/g), color (sensory score) to validate the BNE et al., 2003; Zakaria ZA et al., 2007; Shih CD et al., appropriate drying temperature. 2006; Preethi, Kathirvel et al., 2012; Consolacion Y. 2.2.3 Effect of storage condition to flavonoid (mg/g) in the Ragasa et al., 2015). The incorporation of fruits into routine dried leaf tea diet could prevent the risk of cardiovascular diseases, After completion of drying treatment, the dried Muntingia ageing, inflammations and cancers due to antioxidant calabura leaves were subjected to storage. They were kept compounds present in the fruits (Preethi Kathirvel, 2017). in PET/AL/PE (zipper top), PET/AL/PE (vaccum) bag at Muntingia calabura is an underutilized fruit crop and still different 4oC, 28oC. The flavonoid content (mg/g) will be now there is very limited research available. In order to analyzed in 3 months interval for 12 months. improve the added value of this leaf, objective of this study 2.3 Physico-chemical and sensory analysis focused on the effect of blanching temperature and time; The vitamin C (mg/100g) content of the Muntingia heat pump drying temperature and storage condition to calabura leaves was determined by redox titration using vitamin C (mg/100g), flavonoid (mg/g) and sensory score iodate solution. Flavonoid (mg/g) was determined with of the dried Muntingia calabura leaf tea. reference to the method of Shanmugapriya S. et al., (2017). Color (sensory score) of Muntingia calabura leaves was 2. MATERIAL & METHOD assessed by a group of panelist. They were required to 2.1 Material evaluate the odour, colour, taste, sweetness and overall We collected Muntingia calabura leaf in Ben Tre province, acceptance using the 9-point hedonic scale (1 = dislike Vietnam. They must be harvested from gardens without extremely, 9 = like extremely). pesticide and fertilizer residue to ensure food safety. After 2.4 Statistical analysis harvesting, they must be conveyed to laboratory within 8 The experiments were performed in triplicate. Statistical hours for experiments. They were washed under tap water analysis was conducted by the Statgraphics Centurion XVI. to remove foreign matters. Besides Muntingia calabura leaf we also used another material during the research such as 3. RESULT & DISCUSSION CaCl2. Lab utensils and equipments included digital weight 3.1 Effect of blanching temperature to vitamin C balance, cooker, heat pump dryer. (mg/100g), flavonoid (mg/g) and color (sensory score) in the dried Muntingia calabura leaf tea Thermal blanching is an essential operation for many fruits and vegetables processing. It not only contributes to the inactivation of polyphenol oxidase (PPO), peroxidase (POD), but also affects other quality attributes of products. The purposes of blanching include inactivating enzymes, enhancing