PURPOSE:

Aim of this experiment was to analyze various type of fruit juice about the food quality respects and compare our results with the TSE’s values.

THEORY: Juice is a liquid naturally contained in fruit or vegetable tissue. Juice is prepared by mechanically squeezing or macerating fresh fruits or vegetables without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree. Juice may be prepared in the home from fresh fruits and vegetables using variety of hand or electric juicers. Many commercial juices are filtered to remove fiber or pulp, but high pulp fresh orange juice is marketed as an alternative. Juice may be marketed in concentrate form, sometimes frozen, requiring the user to add water to reconstitute the liquid back to its 'original state' (Generally, concentrates have a noticeably different taste than their comparable "fresh-squeezed" versions). Other juices are reconstituted before packaging for retail sale. Common methods for preservation and processing of fruit juices include canning, pasteurization, freezing, evaporation and spray drying We can classify the fruit juice as;Fruit nectar; %40-50 fruit content, 40-50 % water, 10-20% sugar and additivesFruit juice; pressing of fruit and contains 100% fruit juiceFruit drink; contains at least 10% fruit juiceFruit juice concentrate; contains 60-70 % brix which obtained by evaporating water from original juice.

We can classify the fruit juice according to production;- press line- pulper line- citrus line- filling line

PRESS LINE:raw material

washing

sorting

deseed, core crushing, peeling

fruit pulp

heating

rapid cooling

During washing sand and other materials removes.At heating process natural enzymes inactivates at 60-80ºC, reduced microbial activity, and increased solubility.

Enzyme treatment done to; obtain clear juice. Pectin gives firm structure and gives turbidity to fruit so adds pectoliytic enzymes ( methyl esterase and polygalacturonaze), 3 hr waited at 45ºC so the solubility increase and enhance color and flavor.

During flavor retention ; separates the aromas of juice because they may loose during further heat processes.

To clarify the juice adding pectolytic enzymes.

During evaporation temperature keeps low and uses vacuum about 700 torr.

1

enzyme treatment

pressing

juice

clarification

coolingadding gelatin

holding

filtration

clear juiceevaporating

PULPER LİNE

Crushing

Preheating

Pulper

Dearation

Pasteurization

Cooling

Storage

CITRUS LINE

Raw material

Washing

Brushing

Cutting and extraction of juice

Flavor retantion

1Pulper done in a special rollers that separates residue and pulp of fruit.

During Dearation air in the fruit juice is removes because it cause the oxidation and this process done by applying vacuum.

Pasteurization (or pasteurisation) is the process of heating liquids for the purpose of destroying viruses and harmful organisms such as bacteria, protozoa, molds, and yeasts.

Brushing step done to remove dirts on the skin. Also a special system uses which contains needles on line and this needles drills the skin of fruit and the oil seperates which gives the juice a bitter flavor.

Preheating done at 35-37 ºC

Pulper

Dearation

Evaporation

storage

Turkish codexMinimum fruit content

Fruit juice 100% apple juiceFruit nectar 50% apple

40% peach30% citrus

Fruit drink 30% apple

TSE Standars for Orange Juice (TS 1535)

Chemical Properties   LimitsSoluble Solid Matter(Refractometric) % w/w   min. 10.00Titratable Acidity(citric acid)%w/v       max. 2.0Formal Index       min. 15.00Ascorbic Acid(Vitamin C) mg/l     min. 200.00

DATA:

For fruit juicesGroup Sample Ascorbic

acid mg/mlBrix Acidity Formal index

(100ml juice)B1 Pınar peach 2,037.8 14 0.316 56.8B2 Dimes peach 2,392.2 12.1 0.339 63.2B3 Cappy orange 886 14 0.576 90.4B4 Tamek orange 1,772 11.5 0.784 127.6B5 Pinar apple 974.6 11,6 0.573 92.8B6 Dimes mix 886 12 0.668 92.8B7 Cappy cherry 460 13,9 0.736 123.2B8 Tamek cherry 2037.8 14 0.768 113.2B9 Sek apple 709 13.5 0.640 101.6

CALCULATIONS: Ascorbic Acidg ascorbic acid =0.0886*Vused volume*N(normality of indophenol sol’n)

N of indophenol is 0.1 N Vused =1.0 ml of indophenol sol^n

g ascorbic acid= =886 mg/L

Titratable Acidity1.0 ml 0.1 N NaOH = 0.0064 g citric acid Vused NaOH sol^n =9.0 ml

g citric acid= 9.0*0.0064=0.0576 g % citric acid=0.0576*100/10 = % 0.576

Formal IndexFirst part( until pH increased the 8.50) → 20.3 ml was used

second part( after addition formaldehyde sol^n) → 2.3 ml was used total→22.6 ml

% formal index = 100*22.6/25 = % 90.4

Soluble Solids Soluble soid matter value was directly measured by pouring some amount of juice sample onto the mirror of refractometre.The value was 14.0DISCUSSION:

In this experiment,we worked cappy orange juice to determine its quality attributes fit or not with TSE standard. At formal index test first added 0.1 N NaOH solution until pH of fruit was 8.5. then added 10 ml formaldehyde solution and then again added NaOH until pH of juice was 8.5. By doing formal index test we determine the any synthetic flavor compound which was added or not in fruit juice to make adulteration. Natural flavor compounds are protein structure and produce a.a. and when titrated with NaOH we must use much solution then the synthetic flavor compound added juice.We found the value of formal index was 90.4.The decleared value of formal index in TSE for orange juice is min 15.00.When we compared with it,our result was adequate but compare to the same sample working group,tamek orange which was 127.6,it was lower.Maybe we can say that there is an adulteration for our cappy orange juice sample because the volume of NaOH which was used by our group,was low. Brix content is defines the soluble solid content of the fruit juice.Juice compare to concentrates involves less amount of soluble solids.We found the value of brix was 14.00.The limits which was decleared in TSE for orange juice was min. 10.The other group.tamek orange juice, found the value of brix was 11.5.Both value were fit with TSE.When we compare these groups,cappy producer was added more soluble components than tamek producer. Ascorbic acid determination,10 ml fruit juice taken and added 100ml acidified water and 1ml starch solution. Then titrated with I2 solution. By this manner determined the ascorbic acid value. The ascorbic acid value represents the vitamin C content of the product.We found the value of ascorbic acid was 886.The other group was found the value was 1772.The limit which was decleared in TSE is min 200.00.Both value were fit with the TSE.According to the results tamek producer is present higher amount of Vitamin C than our juice,cappy producer. In this experiment we also determined titratable acidity.It gives us idea about the citric acid which is extended the shelf-life of products.We found the value of acitdity was 0.576.The value which was decleared in TSE is max. 2.00.The other group found the value of acidity

was 0.784.Both are fit with the standard.Tamek producer was used citric acid ,which is a chemical preservatives,than the cappy producer. When we look at the over-all producer; About the soluble solid content value; the lowest value was obtained,11.5, from tamek orange juice producer,the other groups respectively B5>B6>B2>B9>B7>B8=B3=B1. About the formal index value:pinar peach juice producer was the most naturally producer than the others.Because volume of using NaOH was very low compare to other groups. About the acidity;tamek orange juice producer was used more amount of citric acid as a preservatives than the other groups.

About the ascorbic acid value:dimes peach juice producer added more amount of Vitamin C compare to other groups.