Processing of white tea

White tea can be defined by the sub-species it is manufactured from Camellia sinensis var. khenghe bai hao and Camellia sinensis var. fudin bai hao. These species can be found only in Fujian province and with minimal processing following traditional guide-lines. White tea is a seasonal crop (spring) with special sensory and health benefits.

The white tea manufacturing process, that is, tea fresh leaves/buds being dried, is minimal compared to production processes used for other types of tea. Because of that, white tea retains a high amount of its polyphenols, especially catechins.

White tea is often described as 'minimally processed' and 'unoxidized' tea among all type of teas. White tea is prepared from very young tea leaves or buds covered with tiny, silvery hairs, which are harvested only once a year in the early spring. The buds may be shielded from sunlight during growth to reduce the formation of chlorophyll, giving the young leaves a white appearance.

White tea belongs to the group of tea that does not require panning, rolling or shaking. Plucking of young tea leaves with much fine hair can produce good-quality white tea.

The first leaves and buds are selected and subjected to a minimum processing by simple drying. The leaves and buds are allowed to wither in natural sunlight before they are lightly processed to prevent oxidation or further tea processing. The plant materials are steamed and dried immediately after picking to prevent oxidation, giving it a light and delicate taste.

Because there is no oxidation, it contains the most anti-oxidants and catechins, the least caffeine, and has a pale color with a delicate, sweet taste.

The minimal processing of white tea, plus the higher overall proportion of buds to leaf, gives a pale beverage with a slightly sweet, subtle flavor compared with other teas. The basic process for manufacturing white tea is as follows: Fresh tea leaf → Withering → Drying (air drying, solar drying or mechanical drying) → White tea.

White tea is said to be less in caffeine than green tea. White tea is also having much higher in antioxidants, esp. catechins than green tea.
Processing of white tea

Process of evaporation

Concentration of liquid foods is an important operation of many food processes and there are several technologies available, such as evaporation under vacuum and membrane concentration.

Evaporation has historically been the primary technology for liquid concentration in the food industry.

Evaporation removes most of the water resulting in concentrated product which may be used as such or processed further, e.g. by drying.

Evaporation is employed in the food industry to reduce weight and volume of fluids, with subsequent reduction of packaging, transportation, and storage costs. It also used to reduce the energy consumption at the drying operation.

Another important application is the production of fruit (mainly grape, apple, and orange) and vegetable (mainly tomato products) juice concentration.

In the dairy industry, evaporation is used for concentration duties, such as milk, skimmed milk and whey. It is also used as a preliminary step to drying. The thermal efficiency of evaporators for removing water is much higher (e.g 90%), compared to the efficiency of dryers (e.g. 60%).

Evaporation of water from the solution by heating is feasible, but usually the products to be evaporated are heat sensitive and heating can change some their physicochemical characteristics at this elevated temperature. Evaporation might result in crustal precipitation.

Evaporation might also result in foaming of the concentrate. Evaporation at low temperatures, under vacuum, reduces thermal degradation of food properties (textural and nutritional) and aroma recovery schemes allow collection of essential flavors and aroma compounds.
Process of evaporation

Cleaning in place (CIP)

Today, in many food industries, cleaning in place (CIP) is not only a cleaning method but a strategic decision built into the design of the plant and its individual parts.

Among the advantages of CIP:
*Permit on-site cleaning
*Substantial increases in processing capacity
*Reduced losses through the application of CIP cleanable automated vales and highly automated process
*Minimizes downtime
*Improved quality of all products and significant improvement in perishable products
*Reduced labor for both processing and cleaning

An additional advantage is that the cleaning agent/solvent quantities necessary for CIP is less than for conventional cleaning.

Basically CIP is a hydrodynamic cleaning process where rinsing, cleaning and sanitizing fluids circulate along with the path of the products and provide the detergency as well as the mechanical action needed for the removal of soil, without dismantling the line.

It is an economical method of maintaining the processing line at peak performance and extending it operating life. It is recommend that regular CIP cleaning is included in the preventive maintenance program to maximize processing performance and minimize the system operating costs and overall maintenance cost.

With its controlled, monitored, documented and reliably reproducible cleaning result, CIP fulfills the GMP (good manufacturing practices) requirements.
Cleaning in place (CIP)

Quick freezing of food

The two basic ways to achieve the freezing of foods are quick and slow freezing. The technical features of the quick freezing process are ultra rapid freezing at very low temperatures (-30 to -40 ° C) designed to bring the inside the product to a temperature of -18°C as quickly as possible. Rapidly frozen foods have a much longer storage life than foods stored in cold stores.

The products that are generally preserved by quick freezing are meat, fish, some vegetables such as peas, spinach, cauliflower, carrots, beans etc.

When the quick freezing process is used, these liquids solidify to form extremely fine crystals of ice, and the cellular structure is left intact, whereas, in the ordinary freezing process, where low temperatures are reaching more slowly, the texture of the product is altered.

In quick freezing, large quantity of food can be frozen in a short period of time.

Quick freezing is a method of increasing the shelf-life of perishable foods by subjecting them to conditions of temperature low enough to inhibit the oxidative, enzymatic and microbial changes, which are responsible for the changes in flavor and color of foods.

Quick freezing is ideal for producing good quality frozen foods. The food freezes immediately and keeps its shape and appearance.

Quick freezing is obtained by one of the following methods:
*Freezing Tunnel or Blast Freezer
*By Direct Contact with Metal Plate Surfaces maintained at Low Temperatures
*By immersion in (or by Spraying)  a Low Temperature Liquid
Quick freezing of food

The Important of Flavorings in Food

Flavorings are compounds, many of which are natural, although there are also many synthetic ones that are added to foods to produce flavors or to modify existing flavors.

Flavorings are the complex mixtures of individual ingredients which are often natural constituents of food, and can be produce through physical means form traditional plant and animal sources, chemical synthesis and processes incorporating the techniques of modern biotechnology.

Flavoring means adding a new flavor to a food, thus changing or modifying the original flavor.

The flavor substances are comparatively strong smell organic compounds with characteristics, usually pleasant odor.

In the early days of human existence, salt, sugar, vinegar, herbs, spices, smoke, honey, and berries were added to foods to improve their taste or to produce a special, desirable taste.

The range of natural and synthetic flavoring available to the modern food technologists is very large.

Essential oils form a major source of flavorings. Most foods derive their characteristics flavor from chemicals that are present at levels ranging from parts per billion to parts per million.

With the discovery of distillation, it became possible to separate the flavor chemical mixture from botanical material.

Because of their weak effects, fruit extracts may be intensified by combining them with other flavorings.

Flavoring can be added at the beginning, middle or end, depending on the cooking time, the cooking process and the flavoring ingredient.
The Important of Flavorings in Food