Pineapple juice processing

The pineapple tree belongs to the Bromeliaceae family. The edible part of the pineapple fruit (60% of the fresh fruit) has a moisture content of 85%.

Pineapple is largely consumed around the world as canned pineapple slices, chunk and dice, pineapple juice, fruit salads, sugar syrup, alcohol, citric acid, pineapple chips and pineapple puree. Pasteurized pineapple juice is one of the most important pineapple commodities.

The pineapple juice is processed by many advanced processing techniques to reduce bacterial contamination with improved shelf life and preservation of antioxidant compounds, vitamins, and minerals.

Steps production of pineapple juice:
*Receiving of pineapple
*Sorting: removing the crown and leaves
*Washing with water
*Peeling
*Cutting
*Juice extraction
*Juice filtration
*Juice pasteurization: Fresh juice is boiled at 80°C for 30 s
*Cooling

Pineapple juice is often recovered from the ejected skins and cores from the machines which cut the pineapple in preparation for canning.

Pineapple juice can be obtained with an extraction machine only, or, in addition, enzymes can be used to increase the yield and the juice recovery from the pineapple pulp or residue.

The juice contains up to 40% pulp. The pulp content is reduced, usually by finishing with a screw-type finisher followed by centrifugation, before pasteurizations and concentration.
Pineapple juice processing 

Bilberry juice processing

Processing fruit into juice is a popular product option and a way to extend marketing windows and shelf life of the berries. Berries can be frozen after harvesting to reduce the effects of pectin and gelling, as well as to extend utilization beyond the narrow harvest season.

Intact fruits from the frozen berries were thawed. The thawed bilberries then immediately heated to 95 °C for 2 min, and then cooled to 38 °C. Subsequently, the thawed berries were squeezed in a hydraulic juice press.

To improve juice recovery, berries can be treated with elevated temperatures. Heating or blanching the berries before pressing is a common step used in juicing fruits. Cold press extracted juice has a light blue color and delicate flavor, although hot press enzyme treated juice has a deep purple-blue color and stronger flavor.

Juices were pooled and diluted with ultra-pure water at the ratio of 1:1 (v/v). The juices were then cooled down to room temperature in a cold-water bath. The pH and °Brix were subsequently adjusted to 3.5 and 14.0 using sodium hydroxide and sucrose, respectively.
Bilberry juice processing

Palm syrup

Palm honey or palm syrup is from naturally grown palm trees. Most of this syrup is locally consumed and traditionally processed as the bottled palm juice, palm wine, and palm sugar.

Its high caloric content has led to its increasing use as a health food supplement for athletes, children and elderly. Furthermore, demand for this natural syrup is continuously increasing due also to its medicinal uses in homeopathic medicine.

In the tropics, palm sap is drunk as such (fresh, or pasteurized and bottled), evaporated for palm syrup and sugar, or fermented to alcohol and vinegar. Palm sap is also a source of yeast for bread making. Fresh sap is sweet, oyster white color and translucent, with nearly neutral pH.

Palm syrup has been traditionally produced from the sap of the tropical palm tree. When palm sap is produced to palm sugar syrup, it takes approximately 6-7 parts of sap to produce 1 liter of syrup. The palm tree sap, known as “guarapo”, is collected from the palm trees in the early spring, when temperatures fluctuate between - 5 and -10 ºC.

Then it must be boiled in a large pot on a wood fired stove until it becomes concentrated. The unique flavour of this natural product develops during this evaporation process (93-110 ºC for 1.5 h). Evaporation involves removal of water by boiling, with a steam or wood fire using a stove, a pan or a metal kettle. In commercial, an open pan and a kettle are still widely used by manufactures for producing maple syrup and palm sugar syrup.

The resulting syrup is a viscous, sweet liquid, dark with reddish tones. Although this natural product has a similar density to honey, it is less sticky. Palm syrups have a good nutritional value marked by high amounts of sugars (58—75 g/100 g fresh matter basis), minerals (2.1—2.6 g/100 g fresh matter basis) and phenolics (147.61—224.55 mg of ferulic acid equivalents/kg fresh weight). Syrup also presents an antioxidant activity that appears related to total phenolic content.
Palm syrup

Date juice

Date is the most popular fruit in middle-east countries. The fruit is an important product in the world and plays a significant role in the economic and political life in date growing regions.

Date fruits are considered as a good source of sugars. It provides natural sugar in the form of glucose and fructose. According to studies conducted on the physicochemical properties of dietary fiber extracted from date flesh, the dietary fiber concentrates showed some functional properties in the food industry, e.g. high water-holding capacity, high oil-holding capacity, emulsifying, pseudoplasticity behavior of their suspensions, and gel formation.

Beside direct consumption of the whole dates, the fruits are traditionally used to prepare a wide range of product such as date juice concentrates (spread, syrup and liquid sugar), fermented date products (vinegar, organic acids) and date pastes for different uses e.g. bakery and confectionary.

Date juice is made by dissolving and diluting soluble solids of date in water and removing insoluble solids. In this operation, stirring, heating, and macerating the date can increase the yield of the process. This product is sometimes consumed as a drink. In contrast with other fruits, date juice cannot be extracted by pressing because of high total soluble solid content.

Juice is pasteurized at 85°C to inactivate the enzyme, cooled and centrifuged at 3000 rpm to get clear juice. Date juice was found to be rich in reducing sugars (16.1%) and total sugars (18.3%).

Date juice has considerable antioxidant and antimutagenic activity and contains strong free radical scavengers. Many products are being made of date juice including carbonated and non-carbonated beverages, ice cream, jam, and jelly as a sugar substitute.
Date juice

Apricot juice processing

Apricot fruit are heated to 99 °C in a thermal screw and then delivered to a pulping unit that removes the pit.

Fibrous material such as the skin is then removed from the pulp by a series of finishers. The resulting juice may be processed into nectar or evaporated into concentrate.

Apricot juice can be enriched by mixing with some additives and other juices. For apple, black carrot is an excellent source of anthocyanins which are the best-known natural red colorant used in foods.

Apricot nectar exhibits a phenomenon of cloud loss, which can be avoided by grinding the pulp very finely. These cloud particles of apricot nectar are composed mainly of individual apricot cells, a small part of broken cells and cell wall fragment and other aggregates.

In the fruit pulp the cells contains only primary cell walls consisting of approximately polysaccharides (90%) and protein (~10%).

The production of apricot juice concentrates is mainly based on heat evaporation, which is one of the most used traditional technologies in food industry.

The quality of the end product mainly depends on the temperature gradient between the product and the heat exchanger and high gradient causes local degradation of the product. Apricot concentrate is used as an ingredient in various sauces or for nectar reconstitutions.
Apricot juice processing

Processing of apple juice

The majority of the processing apples are sort-outs from fresh market packing line. The volume available depends on fresh market demand and the quality of the current apple crop.

Apples are processed into a variety of products, but by far the largest volume of processed apple products is in the form of juice.

Apples are brought to the processing building and dumped by the truckload or out the apple bins.

Fruit are then spray washed and sorted. Depending on process logistics, clean, sorted fruit may be stored. Sorting and trimming of apples to remove damaged or decayed fruit is mandatory. If not removed, damaged or decayed fruit may also impart off flavors to the finished products.

Before pressing, whole apples are ground into a mash or pulp for extraction. This mashing process sis accomplished with either disintegrator, hammer, or grating mill.

The type of extraction equipment may dictate the chopping method to achieve highest efficiency. More common types of presses apply pressure via hydraulic, pneumatic, screw, basket or travelling belt methods.

In traditional milling-pressing operations, the yields are 70-80% w/w and even lower (about 65%) for stored apples. However, through use of enzyme liquefaction and membrane filtration, the apple juice yields can be as high as 98%.

For the ‘natural’ look associated with fresh apple cider, the ground apple is treated with ascorbic acid before pressing to minimize browning.

Apple juice is processed and sold in many forms. Fresh apple juice or sweet cider is considered to be product of sound, ripe fruit that has been pressed and bottled or packaged with no form of preservation being used, other than refrigeration.
Processing of apple juice 

Manufacturing of cherry juice

Cherry juice processing can lead to exceptional, high quality, fully colored products without resorting to unusual varietal blends or specialized process techniques. Quality of the product is highly dependent upon incoming raw material and quality of the process.

Juice processing and utilization will vary accordingly. There are two general directions to approach cherry juice production. One is a hot extraction process and the other is a cold extraction process. Both yield a reasonable quality product; however the hot extraction process results in a somewhat higher color extraction and greater amounts of insoluble solids that just be removed in the final filtration operation.

A cold press produces a more fresh flavored juice provided that subsequent processing does not adversely affect flavored. The cold extraction process involves taking fresh cherries, washed and either pitting them or running them through a hammer mill that has been adjusted in order to maintain minimum breakage of pits.

The yield obtained by cold extraction varies from 61 to 68%. Extraction of juice from cherries can be optimized for color with the addition of ascorbic acid and the uses of the short-term mild blanch prior to pressing.

Heating the whole fruit to about 60 °C with gentle agitation and macerating enzyme greatly facilitates juice and color extraction. Depending upon the variety used, the juice can vary significantly in chemical composition.

The freshly juice is rapidly heated to 87.7 – 93.3 °C and then cooled. This operation inactivated enzymes, kills microorganism and coagulates colloidal matter.

Cherry juice is generally clarified and filtered.  The clarified juice can be concentrated with good color retention and for a 100 percent cherry juice. A simple method of preparing the juice for filtration is to treat it with Pectinol.

A possible use of homogenization could assist in leading to stable nectar.

Sour cherry juice is amendable to blends with less acidic juices or as a nectar with added sugar. It is necessary to bring the density of the juice to about 17 Brix.
Manufacturing of cherry juice

Fruit juice processing technology

A freshly squeezed orange or fresh pulped and strained apple would supply a fruit juice drink for immediate consumption, but to expect it to maintain its quality for even a day or two was tempting providence.

Actually the technology to produce high quality fruit juice concentrate has been improved considerably over the years.

With the technology benefits of ultra-high temperature pasteurization, aseptic packaging techniques and system, pressed juices can be stored for extended periods with very little deterioration in quality.

There has also been a range of developments leading to the removal of acidity, color and minerals from clear juices such as apple.

Previously reliance had to be places upon the use of preservatives and classical pasteurization at lower temperature and longer holding times. The traditional process of hot filling juice in containers to produce shelf stable precuts is now being replaced by newer technologies.

Enzymes and finishing treatments are widely used in the processing of fruit juices to obtain products of particular specification. It is more oriented towards flavor orientation, nutrition protection and product stabilization though enzyme control and pasteurization.

During the second half of the twentieth century, apart from the continues move towards more efficient means of production and marketing of bottles or canned soft drink products, there was much progress of knowledge about flavor technology.

Further advanced techniques include the use of membrane technology to achieve cold sterilization, freeze concentration, combination of cold and hot processes, accompanied by aseptic filling technology and irradiation technology.

Pulsed electric field technology also has a potential to replace traditional thermal processes for the pasteurization of fruit juice.
Fruit juice processing technology

Extraction of Fruit Juice

Global fruit juice sales hit the 54 billion liter (BnL) mark in 2007 and are forecast to rise 15% by 2011 to 62 bnl. 

Western European currently consume an average of 31 L of juice a year per capita. Juice is growing fast in Eastern Europeans (18 L are consumed annually per capita in Russia) as well as in India and China. 

The extraction of juice from fruit is an ancient art dating from the earliest of records where wine is often mentioned. 

Fermentation of fruit juice so the alcohol content preserved the fermented juice was one of the earliest forms of food preservation by the human species. 

Preserved fruit juices keep their fresh taste and attractive color as long as they are not heated for too long or at too high a temperature. Prolonged boiling or heating changes the taste except with tomato and apricot juice. 

Manufacturer of fruit juice has progressed from the farm or cottage industry into the efficient technology of modern food processing with the rapid changes in most technologies. 

Throughout the temperature area of the world, fruits used for the major quantities of juices are citrus, pome and grape or vine fruits. 

Hand picked fruit is generally of good quality and needs little pre-press treatment, but the growth of automatic harvesting, particularly with apples, creates may new problems of debris and dirt such as leaves stones and twigs, all of which need to be removed prior to pulping. 

Methods of extracting fruit juices are dependent upon the structure and edible portion of the fruit. 

Preservation methods include thermal treatments, freezing, chilling, concentration and for some clear juices, fine filtration. 

Juice may taken apart by removing volatile flavour components, water, bitterness and acidity and then recombined to produce a consistent product. Fruit derived bases may be manufactured from the remaining fruit material after the juice has been extracted. 

Pasteurization is often required to stabilize the product by removing microorganisms that could produce fermentation and/or spoilage, affecting clarity, taste and shelf life.

Extraction of Fruit Juice

Fruit Juice Processing

Fruit Juice Processing
Most juices are derived from fleshy fruits and these may be conveniently subdivided for processing into three categories.

*Fruits which are pulped and their juices removed by pressing, e.g., apple, berry fruits
*Fruits requiring the use of specialized extraction equipment, e.g., citrus fruits, pineapples
*Fruits requiring heat treatment before processing, e.g., tomatoes, stone fruits

In most large fruit processing operations the plant is usually dedicated to one type of fruit.

Citrus fruits are unusual because the outer skin or flavedo is rich in essential oils and other tissues such as the albedo or carpellary membranes contain substances that give rise to bitter flavors.

The processing of citrus typical involves separation of these various components as an important principle and for certain products such as comminuted bases, the various components are recombined in different proportions.

The flesh of stone fruits is separated from the stones or pits, not only to facilitate ease of handling, but also because the stones are further processed to obtain both fixed oils and glycosides.

Fixed oils, such as those from peach, have application in the cosmetics industry and glycosides may be used as a source of other natural flavoring ingredients such as benzaldehyde.

Another important aspect of the processing of fruit is the presence of pectins. These substances contribute it the viscosity of fruit juices and assist in the suspension of colloidal material and tissue fragments that make up its cloud.

When most fruits are pressed, pectolytic enzymes are released and these will of not destroyed, clarify and or cause gelling of the juice.

Rapid initial processing of freshly pressed juice is therefore an important factor in determining whether cloudy juice is obtained (in which case the enzymes must be destroyed by pasteurization to at least 95 degree C) or clear juice, in which case enzymes are allowed to act and may be enhanced by the addition of synthetic enzymes on further quantity.
Fruit Juice Processing

Fruit Juice Processing

Fruit Juice Processing
The extraction of juice from fruit is an ancient art dating from the earliest of records, where wine often mentioned.

Fermentation of fruit juice so the alcohol content preserved the fermented juice was one of the earliest forms of food preservation by the human species.

With rapid changes taking places in most technologists during the past century, the manufacturer of fruit juice has progressed from the farm or cottage industry into the efficient technology of modern food processing.

Throughout the temperate areas of the world, fruits used for the major quantities of juices are citrus (predominantly orange), pome, and grape or vine fruits.

Some production of stone fruit and berry juices is carried out but only in small quantities.

Pineapple dominates tropical fruit juice production, with highly flavored fruits such as mango, passionfruit and guava becoming more popular as blending juices.

Methods of extracting fruit juices are dependent upon the structure and edible portion of the fruit.

Preservation methods include thermal treatments, freezing, chilling, concentration (drying) and for some clear juices, fine filtration.

Juices may taken apart by removing volatile flavor components, water, bitter and acidity and then recombined to produce a consistent product.

Fruit derived drink bases may be manufactured from the remaining fruit material after the juice has been extracted.
Fruit Juice Processing

Guava Juice Processing in India

Guava Juice Processing in India Guava juice and nectar are among the numerous popular canned or bottles fruit beverages in tropical areas. A clarified guava juice can be used in the manufacture of clear guava nectar, clear guava jelly, or in various juice blend drinks. It has light amber, yellow, or light pink color, depending on the cultivar, since most of the pigments in the guava remain with the solid material. 

In India, clear guava juice is prepared from the white-fleshed ‘Allahabad’ variety according to the following steps: washed and trimmed fruits are blanching for 3 – 5 min to inactivate the oxidative enzymes prior to pulping; after blanching, the fruit is passed once through a screw press fitted with a coarse sieve of 20 – 30 mesh; and the residue is passed through again for maximum recovery of the pulp. 

Two types of cloudy guava juice are prepared in India: one product contains 55 – 60% pulp, and the other consists of 85% pulp. The soluble solid content of the guava pulp is around 13 – 14 Brix, and the acidity is 0.20 – 0.25%. The pulp, citric acid and 70 Brix syrup are heated and blended, yielding a final 15 Brix and 0.20 – 0.30% acidity. 

Ascorbic acid is added at the rate of 0.01%. The prepared product is poured hot into bottles, capped and processed in boiling water for 25 minutes followed by cooling to ambient temperature. Guava juice is further processed and utilized in the form of concentrates, beverages, jellies, powders and other products. 

Guava juice can be concentrated to five times its original content of total soluble solids. But the color of the juice changes to brown because of browning. Guava juice concentrate has been found to be suitable for drying onto guava juice powder and ready to serve beverage. 

Guava Juice Processing in India

Fruit Juice Processing

Fruit Juice Processing
The majority of fruit juice is made by reconstituting concentrated juice with water to a composition as similar to that of the original state. However, since records are not usually kept of the exact quality of the original juice, such reconstitution normally relates to an agreed trade standard. Reconstituted juices are often packed in aseptic long life containers such as TetraPaks.

There are many countries a growing market for fresh ‘single-strength’ juice made by squeezing fruit. Subjecting it into some processing, packaging it selling it within a cold chain distribution system. Such juice is usually referred to as ‘not from concentrate’ and will have a shelf life that varies from 1 or 2 weeks to 2 or 3 months.

In general terms, fruit are collected, sorted and washed, and then subjected to a type of mechanical compression appropriate to the fruit concerned. Although there are general fruit presses that can be used for more than one fruit type, fruit such as citrus, pineapple and stone fruits are usually processed in specially designed equipment.

Some fruit types (such as apples and pears) require mechanical treatment (milling) coupled with a biochemical process (involving enzymes) to break down the cellular structure and obtain best yields. It is possible to achieve almost total liquefaction by means of an appropriate enzyme cocktail.

Additionally, a diffusion or extraction process can be used to obtain best yields from certain fruits.

If juice is to be sold as ‘not from concentrate’ it is usually screened and pasteurized immediately after pressing – an operation with two main objectives. The first is to control the growth of spoilage micro-organisms that live on the fruit surface (mainly yeasts and moulds). The second is to destroy the pectolytic enzymes that occur naturally in fruit that would otherwise breakdown the cloudy nature of the juice. If, however, a clear juice is required, enzymes can be added to accelerate this natural process.

Juice for concentration is normally subjected to screening to remove cellular debris and then fed to a one or multistage evaporation process to remove most of the water and other volatile material. Evaporators today are highly efficient processing unit: up to nine stages are used, sometimes with the thermal recompression to obtain maximum efficiency. Increasingly, evaporators also recover the volatile aromatic substances that are partly responsible for giving fruit juice their sensory characteristics. The re-addition of such volatile is widely practiced at the point when concentrates are reconstituted into single strength juice.

After concentration, juices are normally held in storage until they are reconstituted. Some concentrated juices, particularly orange, require freezing at below -10 degree Celsius for effective preservation. Others, particularly apples, can be held at around 10-15 degree without risk of deterioration. The degree of concentration plays an important part in determining storage conditions: in the above examples, orange juice is normally concentrated to about 65 degree Brix and apple to 70 degree Brix.
Fruit Juice Processing