Canning process: Apple slices

Apples for processing should be sound, mature, reasonable size, and of uniform shape to be peeled. Apples for canned slices must be firm, maintain integrity of the flesh when sliced, and have good color. York, Stayman, Golden Delicious, Northern Spy, Rhode Island Greening, Yellow Newtown, and Jonathan are preferred for making slices.

The stem tips were removed and fruits immersed in chlorinated water (300 ppm) for 20 min. Fruits were either subjected to hand peeling, steam peeling or lye peeling. In steam peeling, the fruits were exposed to live steam at 100 °C for 6-8 min. Fruits were also soaked in either 5 or 10% lye solution for 30-60s at 28-3 °C.

The slicing operation is usually an integral part of the peeling and coring process where the apples are sliced into 12 to 16 pieces in the coring section. After slicing, the apples are inspected for defects such as blossom or calyx, carpel tissue, skin, and bruises and are conveyed over a shaker screen to remove small chips. Apple slice texture is very important. Therefore, apples with firm flesh and high quality are desired. Consistency of slice size can be controlled by using fruit from within a preselected size range.

Adding syrup to canned fruit helps retain its flavor, color and shape. It does not prevent spoilage of these foods. By using syrups offer a new “very light” syrup, which approximates the natural sugar content of many fruits.

In canning regular fruits without sugar, selecting fully ripe but firm fruits of the best quality is very important. Prepare these as for hot-packs but use water or regular unsweetened fruit juices instead of sugar syrup. Juice made from the fruit being canned is best. Blends of unsweetened apple, pineapple and white grape juice also are good for filling over solid fruit pieces.

The canned apples must be processed immediately after closing to a can center temperature of 82.2°C; there are several types of sterilizers available, Batch retort vessels, and continuous rotary cookers that operate either at atmospheric or pressurized conditions. Immediately after sterilizing, the cans should be cooled at 37 to 40°C to prevent “stack burn” or loss of product color in storage.
Canning process: Apple slices

Processing of cranberry jelly and cranberry sauce

About 80% of the cranberry crop is processed. Some of the processed berries are made directly into cranberry juice drinks and traditional types of cranberries sauces.

In manufacturing cranberries jelly, the clear juice from the boiled fruit that has been passed through a pulper, is nixed with sugar, about 0.35% of dispersed pectin is added and no water used.

The mixture is heated briefly to bring the soluble solid content to 65% and citric solution is added to regulate the pH 3.0 to 3.2.

Cranberry sauce production starts with frozen fruit. After the frozen fruit is dumped into warm water for defrosting the slurry passes through scavenger and rock trap prior dewatering and cooking.

For whole cranberry sauce carefully hand-sorted berries are added to the puree after the first cooking. No additional pectin is needed to set the jellied sauce because the berries have an abundance of natural pectin.

Both cranberry sauce and cranberry jelly are preserved by heat processing. If the products are heated to about 190 F (87.8 C) prior to filling into containers further heating is not necessary to attain commercial after sealing the containers.

If packed at lower temperatures, the containers should be sealed and heated in a water bath or with spray of water at 185 – 200 F (85-93.3 C) prior to cooling.
Processing of cranberry jelly and cranberry sauce

What is banana essence?

United Brands developed the first commercial all-natural banana essence and began marketing it in 1982 to be used in desserts toppings, juices and drinks.

Banana fruit has a pleasant flavor. Researchers have identified a total of 43 and 26 volatile flavor compounds in banana essence and fresh bananas, fruit paste, respectively. These volatile compounds included alcohols, esters, aldehydes and ketones.

During the processing, once the peels are separated the mashed bananas are passed through screens that vary in size and type. The puree is then homogenized.

The next process step, de-aeration, is one of the most important in determining the color of the finished puree. During the de-aeration under vacuum, the air present in the puree is removed to a large extent. The volatile components of the banana aroma are also removed and are condensed to produce banana essence.

Banana essence, extracted from ripe fruit, is a clear, colorless liquid which has an agreeable, concentrated aroma and is used in desserts, juices and drinks.
What is banana essence?

The uses of raisins

Raisins didn’t become popular in Europe until the 11th century when knights returning home from the Crusaders brought raisins back with them from the Mediterranean and Persia.

Raisins are one of the most popular types of dehydrated foods products. Raisins are dried fruit of various kinds of grapes that contain considerable sugar and are cured in the sun or in an oven.  As a dried fruit, they are a concentrated source of calories and nutrients, including vitamin B6, copper, iron, magnesium, manganese, phosphorus, potassium and thiamin.

They are also high in dietary fiber and have no cholesterol. Today, raisins are made similarly the world around. The grapes are handpicked and spread in rows between the vines to dry in the sun. Their bloom – the coating of natural yeast that cling to all grapes – remains intact and the dried grapes turn almost black.

Raisin can be eaten as a snack, either alone or mixed with nuts and either dried fruits. They are stirred into yoghurt, added to cereal and oatmeal, used in breads and cakes.

Like other fruits, raisin should be washed thoroughly before they are used. They may then be soaked in warm water and stewed in exactly the same way as prunes.
The uses of raisins

Lemons

Lemons
Lemons trees may be grown from nursery root stock, but mostly the fruit is grown on graft made on stock of the sour orange.

Once established, the trees may bear fruit for many years. Since the trees, and particular the fruit, are damaged by freezing temperatures, they may have to be protected in cold weather.

Lemons are produced in United States, mainly in California and Arizona.

They are harvested when the skin in green or silver in color and ripened to a yellow color in bins, the air of which contains some ethylene.

Most lemons are marketed in the fresh state, and as such are handled in much the same manner as are grapefruit.

Cooled to about 32 degree F and held at this temperature, fresh lemons have a storage life of 1 – 4 months.

Some lemon juice is prepared and frozen as a lemonade concentrate. The fruit is washed, sized and inspected, after which the juice is extracted and screened.

Sugar is added to provide a soluble solid to acid ration of 14:1 – 19:1. The mixture is then evaporated at low temperature under vacuum to provide a 5:1 concentrate.

The screen pulp (which contains some liquid) is then added to the concentrate to provide 2.4 – 4% pulp by volume.

The concentrate mixture is frozen to a slush having a temperature of 25 degree F ( - 3.9% degree C) in a refrigerated heat exchanger.

The slush is filled into cans, the cans sealed and conveyed through a cold air tunnel until the product is cooled to a temperature of – 18 degree F (-27 degree C) or lower.

Some lemon juice is evaporated to a concentration of about 2:1 and packaged in glass or plastic containers with 0.1% sodium benzoate. Pulp and sugar are not added to this product, which requires no refrigeration. Pectin is manufactured from lemon peel as in the case of grapefruit.
Lemons

Processed Banana

Processed Banana
Bananas are considered the fourth most important food crop in the world, after the three main cereals rice, wheat and corn.

World production statistics are not very accurate as in many countries bananas are produced in home gardens or small plots that often escape the reporting.

For many years fresh bananas have had the highest per-capita consumption of any fresh fruit in the U.S. They displaced apples in the early 1990’s.

In the tropical countries of all continents, bananas have been a staple food for centuries.

The seedless bananas consumed today in the industrialized countries are the result of long painstaking selection and breeding, some done by our primitive ancestors.

Until a few years ago banana seeds from seminal verities were used in breeding. Tissue culture is widely used at present to improve the verities.

Although fresh bananas are widely consumed in develop countries, the consumption of processed banana products is less than that of other processed fruits. Several attempts to launch consumer products such as canned sliced bananas in syrup have failed.

This is partially because fresh ripe bananas are readily available year-round, even in the northern countries, thanks to a remarkable logistics and marketing system.

On the other hand, seasonal crops such as apples produce an abundant crop in a short time.

In the not too distant past, the only way to use so many apples in the short crop period was to process them into products such as juice and applesauce.

There is no such pressure with bananas, they are produced any time of the year with little volume variation.

Therefore, the volume of processed banana products has developed slowly. Also this situation makes the quality of the processed banana products vulnerable to comparison with the readily available fresh “real thing.”

Canned peaches in syrup do not resemble fresh peaches in flavor and aroma, but between crops one either has canned peaches or no peaches at all.

Processed bananas are still produced mostly from rejected of the fresh banana trade. Therefore, the varieties used are the same as for fresh fruit, but there has been a decline in the number of varieties being grown, resulting in only a few selected varieties and sub-varieties of the Cavendish type being used for processing.
Processed Banana

Citrus

Citrus
Botanically, citrus varieties are forms of berry fruits n which the hairs inside the ovary walls form juice sacs.

Epicarp is the familiar highly colored, oil bearing outer layer. Both juice and oils are now valuable commodities in all citrus varieties and the recovery of both material is important to the economics of processing.

Many different processes are used world-wide for citrus types with a two stage operation being widely employed. In a typical process, the fruit passes over an abrasive surface or roller where the sacs in the epicarp are pierced and oil washed away by water spray.

The resulting oil-in-water emulsion is screened to remove vegetable debris and oil is separated by centrifugation and then dried and packed.

The rasped fruit then moved onto an extractor where the juice is removed leaving albedo (pith) and peel (flavedo).

Various juice extractors have been used with fruit being encompassed in a roll mill or screw press, or the juice bearing material reamered out.

Expressed juice is subjected to screening (sometimes referred to as finishing) before being further processed.

Limes are normally processed in a slightly different manner. Washed fruit is compressed in a screw press to yield a pulpy juice that typically also contains the oil emulsion.

Larger pieces of pulp are screened out and in the classical process, juice and oil emulsion are fed to large tanks where a natural separation process occurs.

Naturally occurring enzymes, which may be enhanced by the addition of commercially available synthetic pectolytic enzymes, clarify the juice while the oil bearing emulsion and pulp settle to the top of the tank. At the same time other debris settles below the clarified layer.

Clarified juice is then typically filtered and concentrated while oil bearing emulsion is steam distilled. The process often requires a period of some hours of heating before actual distillation starts and it is in this way that the oil is brought to the specification required by the consumer.

Stream distillation of lime oils usually brings about a number of changes to the components present in the undistilled oil.

The fate of citrus juices both during and after processing will vary with their subsequent use. Whereas lime juice us normally available only as a clarified juice, lemon and orange juices are available both clear and cloudy.

Because of the very high natural acidity (up to 8% s citric acid) of lime and lemon juices, clarification can take place using unpasteurised juices which will not normally ferment.

Orange juice must be treated differently. Clarification is carried out by addition of pectolytic enzymes after pasteurization to destroy microbiological activity.

As with soft drinks fruit juices, the bulk of citrus are subjected to concentration to facilitate shipping and during the process, volatile component are usually collected separately from the juice concentrate.

Both oil an water phase volatile fractions are collected from processes and these are widely used in flavorings.
Citrus

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

Blueberry: Highbush and Rabbiteye

Blueberry: Highbush and Rabbiteye
The blueberry belongs to the Ericaceae family, subfamily Vacciniaceae. Blueberries are found in many areas of the world but have gained greatest acceptance in the US and Canada.

The true blueberries belong to the ancient genus Vaccinium, subgenus Cyanococcus.

The blueberry has specific requirements regarding climate and soil.

The blueberry is a many seeded berry with small, soft seeds that allows it to be accepted by consumers who do not find the seeds objectionable.

Blueberries are a fast growing fruit crop with the fruit maturing 2 to 3 months after flowering.

After reaching its permanent color, the blueberry changes little in size and continues it improve in flavor and sweetness.

There are both wild and cultivated blueberry species. Blueberry varieties originate form the hybridization and breeding of native wild species.

Blueberry varieties are classified as early, early midseason, midseason, late season and late season according to time of maturity.

The cultivated blueberries are highbush and rabbiteye. The blueberry harvested commercially but not cultivated is the lowbush.

The highbush blueberry (Vaccinium corymbosum and Vaccinium australe) range in height from 1.5 to 7 m (5 to 23 ft) and like sunny, acidic areas with a pH between 4 and 5.

These blueberries are shallow-rooted plants and are characterized by the lack of root hairs.

These fine, fibrous roots require an open, porous soil for ease of growth. Blueberry roots are associated with mycorrhizal fungi in the soil that aid the plant in nutrient in nutrient absorption.

These blueberries usually require 6 to 8 years to reach full production. Fruit for use in the fresh market is hand-harvested while machine harvested fruit goes mainly to the processing market.

Major production areas are Michigan, New Jersey, North Carolina, Arkansas, Washington, Oregon, British Columbia, Canada, Europe, New Zealand and Australia.

The rabbiteye blueberry (Vaccinium ashei) can attain heights of approximately 10 m (33 ft) and re extremely vigorous, productive types with fruit similar to that of the highbush cultivars.

Rabbiteye are not winter hardy, but are drought tolerant. In the US, they are grown primarily in the southeastern areas.

It has a short chilling requirement, tolerant to a relative wide soil pH range and high temperatures.

Result suggest fertilization and fruit set of pollinated rabbiteye blueberries can be greatly impaired by even mild freezes (-1 to -2 degree C), whereas, appropriately timed applications of gibberallic acid can result in little reduction in fruit set even after moderate freezes ( -3 to -4 degree C) of blueberries during bloom.

This fruit can be hand or machine harvested.
Blueberry: Highbush and Rabbiteye

Processing of Apples

Processing of Apples
For production of apple slices, apples are size graded peeled, cored, sliced and immersed in a 3% salt solution.

Just before filling into cans, the slices are rinsed to remove salt. They are then filled into can with 40% sugar solution, the cans are then heat-exhausted, sealed and heat processed.

For the production of frozen apple slices, there are number of procedures , but basically, the slices are immersed in brine subjected to vacuum (in order to remove air), re-immersed in brine, washed and packed with sugar in a ratio of 4 fruit to 1 sugar, the product is then frozen. One method differs in that a bisulfite dip is included to prevent non enzymatic browning.

Some apples are dried, although the volume of this type of product has decreased in recent years. For drying, the peeled, cored and sliced apples are first treated in a weak solution of citric and a bisulfite dip. The bisulfite provides sulfur dioxide that inhibits enzymatic browning.

The sulfured slices should be held in refrigerated storage for at least 24 hrs to allow the sulfur dioxide to penetrate the apple slices, the apple slices are eventually spread in the slatted floors of natural draft, loft-type kilns. In the kilns, heated air rises through the apples slice and removes moisture.

After the moisture content has reached about 10%, the apples are packaged in moisture proof containers to be used in the bakery trade.
Processing of Apples

Fruit Processing

Fruit 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 typically 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 fruits is the presence of pectins. These substances contribute to 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, if 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 or clear juice, in which case enzymes are allowed to act and may enhanced by the addition of synthetic enzymes in further quantity.
Fruit Processing

Processing of Raisins

Processing of Raisins
Raisins are produced from grapes by sun during and artificial drying. In sun drying, the grapes are picked as bunches and placed in a single layer on wooden trays between the rows of grapes vines. The trays are tilted to face the sun. After they are partially dried, the grape bunches are turned and allowed to dry to the point where no juice can be pressed out. The trays are then stacked, and the air drying is continued in the shade until moisture content of about 17% reached. After drying, the raisins are placed in sweat boxes to equilibrate, or to even out, the moisture that is present, and then they are packed in retail size containers or in larger containers to be sold to the bakery trade.

In artificial drying, grapes are first dipped n 0.25 – 1 % lye (sodium hydroxide) solution at 200 – 212 degree F for 2 – 5 sec to remove a natural wax that impedes drying and to check or crack the skin of the grape to facilitate drying, They are then washed, placed on trays, and treated with sulfur dioxide to prevent enzymatic and nonenzymatic browning during drying. Hence instead of having the dark brown color of raisins that normally be expected, the raisins will be of a light yellow color when dried. Raisins are dried at temperatures not exceeding 165 degree F and at a low relative humidity. After the moisture content has been lowered to about 16 – 18%, the raisins are packaged in containers of various sizes to be sold at retail or for use by the food industry.
Processing of Raisins

Strawberries

Strawberries
Different variety of strawberries are grown in many areas of the United States, harvested in the winter and spring in southern states and in late spring and summer in northern states. Strawberries require fertile soil; hence soil treatment with fertilizer is usually required. Strawberries are planted as 1 year old plants that produce the next year. The strawberries planted is a perennial that, if properly cared for, will produce for several years.

For handling in the fresh state, they are usually picked with the calyx or cap intact, since this enhances the keeping quality of the fruit. For processing, the berries are picked without the cap. The berries are placed in baskets of 1 Ib (454 g) capacity, and the baskets are placed in crates for transportation to the processing plant. At the processing plant the berries are washed, inspected on belts to remove green and rotten specimens, and then repacked in baskets and crates for shipment as fresh products. They are then cooled to 31 to 32 degree F and should be held at this temperature until sold to the consumer. In this condition, they have a storage life of about 10 days. In some cases, strawberries for the fresh trade are precooled in refrigerated water.
Strawberries

Processing of Raspberries

Processing of Raspberries
At the processing plant, the fruit is washed with gentle sprays of water and drained on a metal mesh belt. If the product is to be handled in the fresh state, it is placed in small, retail sized baskets usually with a cellophane over wrap and quickly cooled to 31 to 32 degrees F. In this condition, the fruit has a storage life only 5 – 7 days.

Some raspberries are frozen for the bakery trade and many for the manufacture of raspberry jam and jelly. To prepare them for freezing, the washed and drained berries may be placed in wooden barrels without sugar, and then placed in a room at 0 degree F or below and allowed to freeze slowly. Usually however, they are mixed with sugar (three parts fruits to one part sugar) then packed in slip cover cans of 50 Ib capacity. The covered fruit is allowed to freeze in cold rooms at 0 degree F or below.

In the manufacture of jam, the deforested fruit is passed through a pulper that allows essentially all the berries with the seeds to pass through the strainer. Sugar and water are then added the amount of sugar depending on whether the frozen product was packed with or without sugar. About 0.1 – 0.15% dispersed pectin is then added and the product is heated in open kettles to concentrate it to soluble solids content about 68%. Citric acid solution is then added to adjust the pH to 3.3 and the fruit is packed in glass jars and vacuum capped. The jars of product are then heated to bring the temperature of all parts to about 160 degree F after which the product is cooled.
Processing of Raspberries