Instant herbal tea contains numerous compounds with medicinal and nutritional value that are beneficial to human health. It is convenient to use, suitable for modern lifestyles, and produces no tea residue or waste after consumption. Instant tea is widely used in the military, aviation, maritime transport, mining, tourism, and many other sectors. It can be consumed as a refreshing beverage or utilized as a medicinal herbal product. As a result, market demand for instant tea products continues to increase.

Figure 1. Color of Instant Knotgrass Tea Infusion

Harvesting

Knotgrass (Polygonum aviculare L.) is harvested at the appropriate maturity stage, approximately 9–10 weeks after planting. Harvesting should be carried out on dry, sunny days, preferably in the early morning or late afternoon.

Removal of Impurities and Washing

After harvesting, the raw materials may contain impurities such as weeds, straw, debris, and other foreign matter, which must be removed to ensure the quality of the materials used for processing.

Following impurity removal, the plant materials are thoroughly washed under running water to eliminate dust, soil, sand, and other contaminants adhering to the leaves, stems, and roots. The washing process also helps reduce the number of microorganisms present on the plant surfaces.

Drying

The knotgrass materials are dried at 50°C until the moisture content reaches approximately 13%.

Extraction

The dried herb is blended with flavor-enhancing medicinal plants, including:

• Stevia (Stevia rebaudiana)
• Cogon grass root (Imperata cylindrica (L.))

The herbal mixture is then extracted using water as the solvent under the following conditions:

• Herb-to-water ratio: 1:5
• Extraction time: 3 hours
• Extraction temperature: 60°C

Filtration and Concentration

After extraction, the herbal residue is removed through filtration.

The liquid extract is then concentrated at 60°C until a thick extract is obtained.

The filtered knotgrass residue is subsequently composted with Trichoderma sp. fungal inoculants to produce organic fertilizer, contributing to environmental sustainability and waste utilization.

Spray Drying

The concentrated extract is blended with Tablactose and subjected to spray drying to obtain a dry herbal extract (instant tea powder) with a final moisture content of approximately 4%.

Packaging and Storage

The instant tea powder, with knotgrass as its principal ingredient, is packaged and stored under suitable conditions.

Shelf life: 12 months.

Processing Flow for Instant Knotgrass Tea

Harvesting → Cleaning and Washing → Drying → Extraction → Filtration → Concentration → Spray Drying → Packaging and Storage

Product Characteristics

The final instant tea product is a fine powder with a light grayish-white appearance. It possesses a mildly sweet taste with a slight bitterness characteristic of knotgrass.

The powder dissolves completely in water, producing a clear solution with a yellowish-brown color.

Figure 2. Instant Knotgrass Tea Product

The processing technology not only preserves the medicinal and nutritional properties of knotgrass but also creates a convenient, easy-to-use product suitable for modern consumers while promoting the efficient utilization of herbal resources.