THE WASTE OF FRUIT AND VEGETABLE INDUSTRY

In fruit and vegetable industry, it is natural that some wastes occur when selecting, sorting, boiling processes are done. Processing of fruits and vegetables produces two types of waste - a solid waste of peel/skin, seeds, stones etc -a liquid waste of juice and washwaters. In some fruits the discarded portion can be very high (eg mango 30-50%, banana 20%,orange 30-50%). Therefore, there is a serious waste disposal problem, which can lead to problems with flies and rats around the processing room, if not correctly dealt with. If there are no plans to use the waste it should be buried or fed to animals well away from the processing site. Quantity and quality of wastes is important on the decision of evaluation of wastes.

Solid wastes

There are a number of possibilities for use of some types of solid fruit and vegetable wastes but there is as yet no evidence that any of these are economic. It is stressed that a full financial evaluation should be done before attempting to introduce any of the ideas below.

One of the main problems in using fruit wastes is to ensure that the waste has a reasonable microbiological quality. Only waste produced during the same day should therefore be used - it is not advisable to store-up wastes to use for example at the end of a week's production. Even with this precaution the waste is still likely to contain mouldy fruit, discarded during processing, insects, leaves, stems, soils etc which will contaminate any products made from it.

Therefore, it is necessary to ensure that some preliminary separation takes place during processing (eg peel and waste pulp into one bin, mouldy parts, leaves, soil etc to another which is discarded, stones, seeds etc into a third bin).

The six main products that can be considered are as follows: Candied peel, Oils, Pectin, Reformed fruit pieces, Enzymes, Wine/vinegar

Tomato wastes

Significant amounts of tomato waste are produced at the growing and early processing stages. Of the tomatoes grown by local growers for tomato paste 49% is lost as unharvested fruit or in such a poor condition and poor colour (green) that it fails to meet the quality criteria for the paste. As these tomatoes are specially grown for paste production there are no other markets available to the growers.

Tomato based waste continues to be produced along the supply chain although losses are not as great as that for the growers. At the paste production stage, almost 10% of the total tomato paste produced is discarded due to failure to meet quality standards. These presents a difficult disposal problem as the paste requires a method of biological treatment before being sent to landfill. Tomato based waste losses of 2% continue at each stage of the supply chain subsequent to paste manufacture. While these may not be considered excessive, the cost to the organisations concerned can be significant.

Tomato-seed oil (from waste seed of canning processes) is sometimes extracted, chiefly in Italy. An antibiotic, tomatine, is also extracted from the seed.

Tomato seed oil was extracted with supercritical carbon dioxide in a semibatch-flow extractor within the temperature range 313343 K and the pressure range 10.824.5MPa. The extraction rates increased with pressure, but decreased with temperature increase because of the variation in solvent density and resultant differences in oil solubility. The fatty acid composition of the extracted oil was similar to that of soybean oil. (GOTO ,1996)

Seed cake contain %33 protein , so it is a good feed material.

Also licopen and oligosaccharides can be obtained from tomato wastes.

Peach wastes

In general the evaluation area of fruits like peach and apricot is fermentationtechnology. Some fruits which have soft seeds can be used in pectin and cellulose production. According to some researches; peaches, which are remains, are about 12000 ton, wastes which cannot be evaluated are about 800000 ton in Turkey. Remains and wastes of peaches, which are suitable for pectin production,show high quantity.

1.1.Evaluation of residue

Remains and wastes of peaches are softened in the high steamy cooker, the seeds are taken out and pulp is obtained with being passed through firstly 2 mm then 0,33 mm palpers. If dry component of this pulp is insufficent, it can be regulated with adding molasses or sugar. Pulp is taken to fermantation tanks, then is inoculated with alcohol yeasts and nitrogenous compounds are injected if necessary. Tempeartures in the tanks are regulated, fermantation is kept under control with mixing. The surface of tank is covered with CO2or SO2. With this ype of fermentation, least %4 and most %8-10 alcohol production can be supplied.

Vinegar can be obtaied with asetic asid fermentation from % 4 alcohol. Drinkable alcohol can be obtained after application of graded distillation. Brendi which is nice alcohol with peach aroma. According some researches,6 litre brendi with %43 alcohol can be obtained from 100 kg peach waste. The peach residue which get out from palper ve siclons cannot be evaluated directly. They should be dried. The peach residue is about 900-1500ton/yl from peach processing in Bursa, 1 kg dried residue is obtained from 6 kg wet residue. 150-250 ton/yl feed substance can be obtained.

Table. According to years dried peach residue composition (dry basis)

Analysis

1974-76

Average

Water (%)

3.6 6.7

5.3

Protein (%)

6.64 8.5

7.48

Fat (%)

1.38 1.63

1.44

Ash (%)

2.79 3.16

2.93

Component without N

70.34 76.95

76.64

Cellulosse

12.20 16.60

14.80

If hygienic conditions are suited, it can be used in the human nutrition because it has got high cellulosse content. It can be used especially in low calorie food, intestine diseases andas digestive system regulator. This residue composition is seen on table.

1.2.Evaluation of seed

The evaluation of seeds of fruits like peach, apricot, plum, cherry show difference because of sourness of seed. Sweet apricot seed is evaluated as candy and nuts. Others are evaluated on different purposes. Peach apricot and bitter almond are not used as food material because they has amigladinwhich is poisonous glikozid. It has seen that cattle animal are poisoned because of this material.

This amigladin glikozid is ceased with 3 methods:

1. 72 hour it is waited in water and at each 24 hour water is changed.

2. Distillation with steam

3. Hydrolysis with acid

Table. Peach seed composition

Analysis

Ratio (%)

Moisture

4.72

Protein

23.86

Fat

38.88

Cellulose

18.60

Ash

3.74

Component without N

14.94

Peach seed composition is seen on the table.

The fatty acid composition of seed almond is seen on the table. It is richer in oleic ve linoleic asids than tomato seeds. Peach seed oil can be used as edible oil, also it can be used in soap production. It should be refined for using as edible oil.

Table . The results of analysis of the fatty acids of peach seed almond

Fatty acids

Ratio (%)

Palmitic asid

8.02

Stearic asid

0.31

Oleic asid

55.14

Linoleic asid

36.53

Amigdalin is remain in the residue after taking the oil. The residue is grinded, wetted and let to distillation with steamd to cease this material. Benzaldehit, which give typical smell to almond, is used as aroma giver in foods. Benzaldehit gather under the vessel in the distillation and the residue without amigdalin is used as animal feed.

The covers of seed are good fuel. This cover can be turned to wood coal with different processes.

3Evaluation of the wastes of citrus fruits

The products, which are obtained from citus fruits, are concentrated, fruit juice, gaseous drinks. The covers of these fruits ar not eaten, so waste quantity is high.

Cover waste with fibre and residue is evaluated on animal feed, cover oil production, pectin cover candy, brendi and wine production.

3.1 The evaluation of covers as animal feed

The all wastes, which remain in fruit juice production, firstly pass lime application. If this application is not made firstly, they stick to press and plug. The wastes with lime come to press. This prevent the sliding of the covers and the falling of the press yield. In lime application press water should be 5.5-7.0 pH. The covers, which are used for animal feed, should be nursed water for chewing of animal easily. The liquid, which come out from press, are concentrated and added to press cake to supply a new moisture equilibrium.

The evaluation of wastes in fruit juice factory

In the study of Yazcolu ve Teke (1978) about the evaluation of debris peach and the waste of peach factory , the evaluation of wastes, which is occured when concentrate is produced from peach, is investigated. The residue of fruit juice factory is dried and mixed with animal feed. This necessitate a technological establishment.

The evaluation of wastes which occur when nectar processing

Marmaladeis a sweet preserve with a bitter tang made fromcitrus fruit,sugar, water, and (in some commercial brands) agellingagent.

In the study of Bal and Grml (1986) the evaluation of wastes are investigated as marmalade. Main raw materail is formed by these wastes and sugar. Pectin, carboksimethyl cellulose (CMC) ve asid (sitric asid) are used as helper. Pectin is used for consistency structure which is very important for marmalade. (Bal and Grml, 1986)

The evaluation of the wastes of frozen fruit and vegetables

When processing of frozen foods is happened, lots of wastes occur. These wastes cause economic loss and form a threat for environment. The factories are obliged to make extra expenses to prevent environmental problems. For evaluating wastes, factories should make research. It is thougt that sauce can made from the wastes of tomato and peppers.

At the research of Aktepe et al. (2006) for recovering residues of the frozen fruit and vegetable production, pasta sauces were created. As a raw material frozen Rio Grande tomatoes and Kapya red peppers residues were used. Amounts of frozen tomatoes and red peppers, garlic, powder of red pepper and other additives were changed during the experiments for the established pasta sauces formulation. Sensorial tests were applied after every experiment and as a result four pasta sauces were selected (tomato, biner tomato, tomato and red pepper mixed, biner tomato and red pepper mixed sauces). These sauces were produced as a small amount at the end of the sensorial evaluation. Then sauces were fihled into glass jars and they are pasteurized at 90C/1 5 mm, after this process they were stored at ambient temperature. Water soluble solid content, total solid content, salt anaiysis, titremetrik acid analysis pH analysis, color analysis, viscosity analysis, sensorial tests were applied to the raw material and final product. And also incubation tests were applied to the final product. The results of the analysis were found suitable with the standards. At the end of the final production, a sensorial test was done and the results were evaluated. As a result of sensorial analysis, bitter tomato and red pepper mixed sauce was chosen as the most delicious sauce. (Aktepe et al., 2006)

Alcohol production from the wastes of dried fruits

Industrial alcohol, which is produced widely, is used as fuel. Also it is used in production artificial silk, colorants, vinegar, drugs and chemical materials, explosive materials, alcoholic drinks.

Nowadays, alcohol production is mostly based on fermentation. Carbon source, which is used in fermantation, should be cheap. Its biological and chemical structure is suitable for requirement of microorganisms. Cellulose wastes, which is the form of biomass,is used mostly. The most realist substrats are hydrolyse polysaccharides or energy products which are sugar store. These can be produced specially or can be wastes which occur in food production. The examples of substrats, which are useed in fermentation, can be the wastes of fruit vegetable, sugar molasses and residue, whey, the waste of starch, cereals brans.

Ethyl alcohol winnes importance and many industry wastes, the churn of sewerage and other solid wastes are used to produce ethyl alcohol. These materials should be passed through some pre-processes and carbon source, which is used in fermentation byshould be form yeast and bacterium, should be formed by hydrolysis. Many methods are applied for this. Wet Oxidation , asid hydrolysis, ADP (Ammoniation Pressurization-Depressurization prosesi) and hydrolysis with cellulose enzyme are some of them. Some combinaions can be applied to increase yield. The most important point is that hydroksi methyl furfural (HMF), which form as side product, obstruct working of yeast. Genetics modified yeasts should be used to prevent this problem.

In a study, cellulose enzyme was used at the en of the two stage hydrolysis to increase sugar yield to %75.%90 ethyl alcohol was produced withSaccharomycescerevisiaewhich is adapted to inhibitors. Ethyl alcohol, which is obtained from fermentation, is seperated with distillation. This alcohol is used as raw material in alcohol drinks and chemical materials. Energy, is occurred with oxidation of ethyl alcohol, is alternative to other energy sources.

In some researches, it is investigated that hydrolysis and fermentation processes are made one after another, some time and economic gain was supplied. But in this method, difference between the temperature of hydrolysis and the temperature of fermentation can cause some problems.

The aim of using process wastes to produce alcohol is meeting necessity, using ofagricaltural and industrial wastes, bringing a solution to environment pollution and obtaining valuable product. (elebi and Gngr, 1997)

Alcohol production from scrap fig

%46,5 of fig, which is produced in the world, is produced in Turkey. %14 of this is scrap fig. Every year 6000 ton fig remain as consumption residue. The best way of evaluation of figs is production of alcohol from fruits which are rich in sugar.

In the study of elebi and Gngr (1997), the optimum conditions in alcohol production from scrap fig were investigated. In this research, fig was used as raw material of alcohol. Most of the sugar content of fig are formed by reduced sugar.

Maya olarakSaccharomycescerevisiawas used as yeast. In this research, The ways were explored to increase ethanol yield of scrap fig to maximum. If the amount of nutrition element, which was added, increased, it was seen that alcohol rate increased.

Fig supplies formation of high rate alcohol. Enzymatic hydrolysis should not be made.Fig contains high rate sugar and %73,97 of this sugar is glucose and fructose (invert sugar). (elebi and Gngr, 1997)

Alcohol production from beet residue

The wastes of sugar facory is used generally as animal feed. This should be used as %70 of total nourishing for goat and sheep and as %45-50 of total nourishing for horse.It contain %8 protein and %0,7 Ca. The amount of Cais very high and it can be accepted as Ca source. But high amount of oksalads which are found in strucure bind Ca and prevent to usage of Ca. The residue contain %30 galactronic asid in the form of pectic substance after sugar extraction. This is main beginning material of C vtamin synthesis.

Fabrikaya gelen eker pancar, yeraltnda yetien bir bitki olmas nedeniyle ncelikle ta ve topra temizlenip, dal ve yaprak ksmlar ayrldktan sonra ykanarak eritler halinde kylr. Pancar eritleri su ile muamele edilip 80Cde kaynatlarak invert ekerlerin ekstrakte olmas salanr. Daha sonra bu karm preslenerek kspe ve ekerli su olarak ayrlr. Bu yolla elde edilen kspe, hayvan yemi olarak kullanlr.

It is though that sugar beet residue is used as raw material for ethyl alcohol production, as energy source. Some researches continue for maximum alcohol production.

Certain temperature and pressure application , asid hydrolysis, usage of cellulose enzyme or wet oxidationare some methods to produce invert sugar which can be used by yeast while yeast produce alcohol.

Residue consist of%27 cellulose. Products which come out with breaking of some cellulosic materials can be used by yeast and other microorganisms. This property cause to win importance on especially fermentation technology as carbon source.

In the study of Ergin et al. (2001), ethyl alcohol was produced from the waste sugar beet residue. Dried and grinded sugar beet was hydrolysed with using of cellulose enzyme.Saccharomycescerevesiae, which is generally used in alcohol fermentation, was used.Alcohol production was investigated with following weight loss. As a result, 13.79 g/l00ml glycose was obtained with using %10 sugar beet residue and%1 enzyme at the end of the 8 hour hydrolysis. % 5,92 alcohol without adding nutriment substances, %6,3 alcohol with adding nutriment substances were obtained at the end of the fermentation.(Ergin ve etin, 2001)

The usage area of ethyl alcohol

Ethanol, also known asethyl alcohol,drinking alcoholorgrain alcohol, is a flammable, colorless, slightly toxicchemical compoundwith a distinctive perfume-likeodor, and is thealcoholfound inalcoholic beverages. In common usage, it is often referred to simply asalcohol. Itsmolecular formulais variously represented as EtOH, CH3CH2OH, C2H5OH or as itsempirical formulaC2H6O

Ethyl alcohol is produced for 3 aim: alcoholic drinks, main material and raw material of chemaical subtances.

As a fuel

The largest single use of ethanol is as a motorfuelandfuel additive. The largest national fuel ethanol industries exist inBrazil(gasoline sold in Brazil contains at least 20% ethanol and hydrous ethanol is also used as fuel). One method of production is through fermentation ofsugar. Ethanol creates very little pollution when burned. Millions more acres of land are needed if ethanol is to be used to replace gasoline. Pure ethanol has a lower energy content thangasoline(about 30% less energy per unit volume). At gas stations, ethanol is contained in a mix of ethanol and gasoline, otherwise known as gasohol. In the United States, the color yellow (symbolizing the color of corn) has become associated with the fuel and is commonly used on fuel pumps and labels.

Alcoholic beverages

Alcoholic beverages vary considerably in their ethanol content and in the foodstuffs from which they are produced. Most alcoholic beverages can be broadly classified as fermented beverages, beverages made by the action of yeast on sugary foodstuffs, or as distilled beverages, beverages whose preparation involves concentrating the ethanol in fermented beverages bydistillation. The ethanol content of a beverage is usually measured in terms of the volume fraction of ethanol in the beverage, expressed either as a percentage or inalcoholic proofunits

Fermented beverages can be broadly classified by the foodstuff from which they are fermented.Beersare made fromcereal grainsor otherstarchymaterials,winesandcidersfromfruit juices, andmeadsfromhoney. Cultures around the world have made fermented beverages from numerous other foodstuffs, and local and national names for various fermented beverages abound. Fermented beverages may contain up to 1520% ethanol by volume, the upper limit being set by the yeast's tolerance for ethanol, or by the amount of sugar in the starting material.

Distilled beverages are made by distilling fermented beverages. Broad categories of distilled beverages includewhiskiesdistilled from fermented cereal grains;brandies, distilled from fermented fruit juices, andrum, distilled from fermentedmolassesorsugarcanejuice.Vodkaand similarneutral grain spiritscan be distilled from any fermented material (grain orpotatoesis most common); these spirits are so thoroughly distilled that no tastes from the particular starting material remain. Numerous other spirits and liqueurs are prepared by infusing flavors fromfruits,herbs, andspicesinto distilled spirits. A traditional example isgin, the infusion ofjuniperberries into neutral grain alcohol.

In a few beverages, ethanol is concentrated by means other than distillation.Applejackis traditionally made byfreeze distillation: water is frozen out of fermentedapple cider, leaving a more ethanol-rich liquid behind.Fortified winesare prepared by adding brandy or some other distilled spirit to partially-fermented wine. This kills the yeast and conserves some of thesugarin grape juice; such beverages are not only more ethanol-rich, but are often sweeter than other wines

Alcoholic beverages are sometimes added to food in cooking, not only for their inherent flavors, but also because the alcohol dissolves flavour compounds that water cannot.

Other uses

Ethanol is easilysoluble inwater in all proportions with a slight overall decrease in volume when the two are mixed. Absolute ethanol and 95% ethanol are themselves good solvents, somewhat less polar than water and used in perfumes, paints. Other proportions of ethanol with water or other solvents can also be used as a solvent. Alcoholic drinks have a large variety of tastes because various flavor compounds are dissolved during brewing. When ethanol is produced as a mixing beverage it is a neutral grain spirit.

Ethanol is used in medical wipes and in most common antibacterial hand sanitizier gels at a concentration of about 62% (percentage by weight, not volume) as an antiseptic. The peak of the disinfecting power occurs around 70% ethanol; stronger and weaker solutions of ethanol have a lessened ability to disinfect. Solutions of this strength are often used in laboratories for disinfecting work surfaces. Ethanol kills organisms by denaturing theirproteins and dissolving theirlipids and is effective against mostbacteria and fungi, and many viruses, but is ineffective against bacterialspores. Alcohol does not act like anantibiotic and is not effective againstinfections by ingestion. Ethanol in the low concentrations typically found in most alcoholic beverages does not have useful disinfectant or antiseptic properties, internally or externally. Ethanol is often used as an antidote in cases of methanol poisoning.

Wine with less than 16% ethanol is vulnerable to bacteria. Because of this,port is often fortified with ethanol to at least 18% ethanol by volume to haltfermentation for retaining sweetness and in preparation for aging, at which point it becomes possible to prevent the invasion of bacteria into the port, and to store the port for long periods of time in wooden containers that can 'breathe', thereby permitting the port to age safely without spoiling. Because of ethanol's disinfectant property, alcoholic beverages of 18% ethanol or more by volume can be safely stored for a very long time.

The production of natural colorants from fruit and vegetables

Pigments are characteristic quality criteria of food so they are important. Natural food colorants can be classified into 5 groups:

Anthocyanins

Carotenoids

Chlorophyll

Betalaines

Other colorants

Fruits and vegetables include natural food colorants in different forms, and these are consumed as part of diet. Lutein and chlorophyll in green vegetabtes, lycopene in tomato, anthocyanins in fruits and vegetables can be given as examples. Natural colorants are extracted from a lot of sources by using developing technology. Pure colorant content of color extract shows differences according to technology applied, and also they include other chemicals. Thats why natural colorants are not only pure pigments, and they form from mixture of pigments that can be extracted.

(Bal and Grml, 1986)