Drying and Quality

Valverbe produces its tea bags following a supply chain logic that goes from seed to finished product.
One of the most important stages of this process involves drying the herbs, which depends on multiple factors related to conservation, aroma, and the active ingredient content of the final product.
Drying involves significant chemical and physical changes to the plant tissue, and the dehydration process helps stabilize them by stopping the enzymatic degradation processes that affect the plant immediately after cutting.
Our cooperative has invested heavily in this phase, purchasing a unique cold-drying system in Italy – using CFT® technology – which, unlike the traditional hot-drying process, preserves the cell membrane intact, and with it, all the properties of the plant.

Preservation of Plant Properties

The technique consists of recreating the conditions of the evening breeze inside the drying chamber, that is, that moment of the day when, according to the physico-botanical laws that govern the plant world, the exchange between the aerial part and the root system of the plant is activated through the opening of cellular stomata (pores) that had remained closed until then to protect against the heat of the day. The system we use has been programmed to dry approximately 800 kg of fresh plant material in 48 hours. The freshly harvested plants are placed in a hermetically sealed steel structure, inside which a flow of fresh, dry air is circulated that – due to the conditions described above – stimulates the opening of the cellular pores within minutes and with it the outflow of water contained in the tissues. During 2006, Valverbe conducted – on two samples of herbs dried using the two different methods – a first step of sensory research through triple-blind panel testing, and simultaneously a comparison of the active principles present in two samples of herbs dried using the two different methods.

Traditional Hot Drying

Start of Drying

The cell membrane is intact

First stage

Cell membrane rupture and liquid release (6–8 hours of mechanical action)

Ending

Disintegration of the cell membrane with the breaking of the botanical sequence

Cold Drying Adopted by Valverbe

Start of Drying

The cell membrane is intact

First phase

Opening of the cell stomata with the release of vegetation water

Ending

The cell membrane remains intact, and the cell stomata stay open

Cold Drying Adopted by Valverbe

Start of Drying

The cell membrane is intact

First phase

Opening of the cell stomata with the release of vegetation water

Ending

The cell membrane remains intact, and the cell stomata stay open

Traditional Hot Drying

Valverbe for herb sanitization performs a bacterial kill cycle with a silo heated to 115° that brings the herb mixture to a temperature of about 80°C for 3 minutes. The process does not harm the organoleptic properties and active ingredients of the plants by working in the absence of moisture (compared to classical saturated steam systems). The product processed in this way is packed in 10-kg disposable bags ready to be sent for packaging.