FST4822LABORATORY FOR CHEMISTRY AND

TECHNOLOGY OF PLANT AND ANIMAL PRODUCTS

FRUITS AND VEGETABLES BASED LAB:THE EFFECT OF DIFFERENT

HYDROCOLLOIDS ON THE PINEAPPLE CORDIAL

GROUP: GROUP 6GROUP MEMBERS:TEY CHEE SENG 137999SITI FARHIAH BINTI ABDUL MANAN 136430FARHANA YUSOF 136499NUR BAITI SOFYUDDIN 136786AMINAH LET 137176FARHAH IZZATI SHUKOR 137259YONG XIANGPEI 138713SEE HUI YONG 138835 PROGRAM : BACHELOR OF FOOD SCIENCE & TECHNOLOGYLAB : MAKMAL PEMPROSESAN & MAKMAL BIOKIMIADATE : 13 AUGUST 2008LECTURER: PROFESSOR MADYA DR. AZIS ARIFFIN

Introduction:

Fruit cordial is a clear liquid. It is a sparkling, clean, sweetened fruit juice from

which all the pulp and other suspended materials have been completely eliminated

(Vaidya et al. 2000). It is a fruit juice which needs or needs not to be diluted before it

is drunk. In processing of the cordial, normally sugar and citric acid are added to

increase the total soluble solids and also Brix value (Desai, 2000). According to Fruit

Product Order Specifications, a minimum percentage of 30% total soluble solids as

well as a minimum of 25% of fruit juice must be reached at the final product.

Most of the beverage industry accounts for 80% of the production of fruit juices

and concentrates. In market, there are miscellaneous fruit cordials available for

purchase, namely roxelle cordial, orange cordial, lycee cordial and others. The

pineapple cordial has a good quality of nutritional values, where vitamins, minerals,

fiber and enzymes are available for a good digestive system and helps in maintaining

ideal weight and balanced nutrition. Pineapple cordial is a good source of Vitamin C

and minimal fat and sodium with no-cholesterol. Based on the health aspect, experts

believe that it also contains micro-nutrients that protects against cancer. With the

properties of the micronutrients, the blood clots can be broken down and it imparts

beneficial health to the heart. Pineapple juices in the cordial can also kill intestinal

worms other than relieving intestinal disorders and soothing the bile. In kidney,

pineapple juice aids in removing toxic elements in the body with the presence of some

chemicals. Hence, pineapple cordials should be produced widely and education on the

benefits of pineapple cordial should be done to raise the awareness of consumers

towards its benefits.

In this experiment, the processing of pineapple cordial was carried out. The unit

operations, starting from cutting, washing, pulping juice extraction, processing and

packaging were learnt. This experiment was done to understand the processing of the

pineapples cordial from the raw materials. Each of the steps was focused and extra

ingredients such as pectin, carboxymethyl cellulose (CMC), Xanthum gum and

sucrose were added to ensure the quality of end product. In this experiment, the effect

of addition of different hydrocolloids mentioned beforehand was also studied. The

functions of each step of the processing and also the use of different ingredients were

studied to ensure better sensory characteristics, more stable shelf life and also the

higher quality of nutritional values of the cordial.

Equipment and utensils Homogenizer

Brix meter

pH meter

Cutting knives

Board

Grinder extractor

Thermometer

Ingredients

Formulation A B C

Pectin 0.15% - -

Xanthan gum - 0.15% -

Carboxymethyl

cellulose (CMC)

- - 0.15%

Sucrose 0.45% 0.45% 0.45%

Procedure:

Whole fruits were weighed.

Pineapple was cleaned. (Peeled, cut and core was removed). The flesh of fruit was weighed.

Fruits were cut into smaller pieces.

The fruit was homogenized in the grinder-extractor.

The waste was pressed to extract more juices.

The extract was collected and weighed. The pH and º Brix were determined.

Sugar was added to the heated fruit extract until 45% ºBrix value was obtained.

The pH of the cordial was determined and its pH was adjusted using citric acid (3.5 to 4.0).

The ºBrix value of cordial was also determined.

0.15% carboxymethyl cellulose (CMC) was added to the cordial.

The cordial was pasteurizing at 88ºC for 1 min.

The viscosity of the prepared cordial was measured using viscometer.

The cordial was warm (45ºC) filled into containers.

The cordial was stored at room temperature for 4 weeks. During those 4 weeks, storage study was carried out.

Results and Analysis:

Table 1: The weight, percentage of yield of juice extract, oBrix, pH, and

percentage of yield of end product in the processing of pineapple cordial using

different hydrocolloids.

Group1 2 3 4 5 6

Pectin Xanthan gum CMC

Weight (kg)Whole fruit 2.480 2.235 2.730 1.260 2.190 1.220

Cut fruit 1.220 1.185 1.405 1.340 1.100 1.190

Juice extract 1.110 1.015 1.289 1.320 1.280 1.060Cordial 1.400 - 1.925 - - 1.850

% yield of juice extract based on:Whole fruit 41.01 49.44 47.22 104.76 58.45 86.89

Average: 45.23 75.99 72.67Cut fruit 83.20 85.65 91.74 98.51 116.36 89.08

Average: 84.43 95.13 102.72

oBrixJuice 7.4 7.5 9.5 7.0 7.0 7.6

Average: 7.5 8.3 7.3Juice syrup mixture 45.8 47.00 44 45 - 45.0

Average: 46 45 45Cordial 44.8 45.00 49.2 48.5 45.6 48.4

Average: 44.9 48.9 47.0

pHJuice extract 3.73 3.94 3.61 3.64 3.70 3.72

Average: 3.84 3.63 3.71Cordial 3.68 3.54 3.59 3.65 3.52 3.77

Average: 3.61 3.62 3.65

% yield of end product based on:Juice (average) 127.27 - 149.34 - - 174.53

Appearance and viscosity measurement:

Table 2: The appearance and viscosity measurement of the pineapple cordial

produced using different hydrocolloids in duration of 3 weeks.

Group 1 2 3 4 5 6Pectin Xanthan gum CMC

Week 0Temperature(°C) 26.8 26.8 27.9Viscosity(mPas) 25.7 25.5 27.0Shear rate(Pa) 39.90 39.0 41.86Shear stress(1/s) 1550.90 1550.9 1550.90Appearance nice nice niceWeek 1Temperature(°C) 25.8 26.1 26.4Viscosity(mPas) 19.6 20.3 24.5Shear rate(Pa) 30.39 31.54 37.96Shear stress(1/s) 1550.91 1550.90 1550.90Appearance Cloudy

Presence of moldsSedimentation

CloudyPresence of moldsSedimentation

CloudyPresence of moldsSedimentation

Week 2Temperature(°C) 26.15 26.1 27.3Viscosity(mPas) 24.35 19.7 20.9Shear rate(Pa) 37.73 30.59 32.46Shear stress(1/s) 1550.90 1550.9 1550.90Appearance Cloudy

Presence of moldsSedimentation

CloudyPresence of black moldsSedimentation

CloudyPresence of moldsSedimentation

Week 3Temperature(°C) 27.2 27.4 27.6Viscosity(mPas) 23.7 16.3 21.9Shear rate(Pa) 36.30 25.25 33.96Shear stress(1/s) 1550.90 1550.9 1550.90Appearance Formation of thin

layer of black molds on the surfaceSedimentationCloudinessPungent odor

Formation of thin layer of black molds on the surfaceSedimentationCloudinessPungent odor

Formation of thin layer of black molds on the surfaceSedimentationCloudinessPungent odor

Graph 1: This graph showed the weight proportion of pineapple fruits in different

condition before further processing; whole fruit weight, cut fruit weight and juice

extract weight. The difference between the weight of whole fruit and weight of cut

fruit for the pineapple cordial with added pectin is the highest. This indicated high

rate of wastage.

Graph 2: This graph showed the percentage yield of pineapple juice extract based on

different condition: based on whole fruit, based on cut fruit, and based on juice. The

percentage yield of cordial based on juice for the pineapple cordial with added CMC

showed the highest percentage than others.

Graph 3: This graph showed the percentage of soluble solids (°Brix) of pineapple

juice, juice syrup mixture and cordial with different hydrocolloids added. The

pineapple cordial with xanthan gum added showed the highest oBrix value compared

to others.

The pH of Juice Extract and Pineapple Cordial

3.45

3.5

3.55

3.6

3.65

3.7

3.75

3.8

3.85

3.9

Pectin Xanthan Gum CMC

Hydrocolloid Added

pH

Juice Extract

Cordial

Graph 4: This graph showed the pH value of pineapple juice extract and cordial with

different hydrocolloids added. The pH value for juice extract with added pectin had

highest pH value may be due to degree of maturity where it was more matured.

Graph 5: This graph showed the variation in viscosity of pineapple juice for three-

week storage. The viscosity of the pineapple cordial increased in the first week and

decreased in the following 2 weeks.

Discussion:

There are a lot of fruit products available in the market such as fruit cordial,

fruit juices and other beverages. These products are different in their processing

method, sensory characteristics, nutritional values and others. Fruit cordial is defined

as a fruit squash (strained fruit juice) from which all suspended material is completely

removed and is a clear liquid. At the same time, sugar is added for sweetening effect

of the fruit cordial. Fruit juice is a natural juice pressed out of a fresh fruit manually or

mechanically and is unaltered in its composition during its preparation and

preservation processes. Fruit juices are highly nutritive beverages and are rich in

vitamins, minerals, and other nutrients. Besides, they are delicious and have a

universal appeal for their taste, aroma, flavor, and color, when freshly expressed

(Desai, 2000). On the other hand, beverage is a name applied to various kinds of

drinks. In other words, beverage is any one of various liquids for drinking, applied to

drink artificially prepared and of an agreeable flavor. Beverage is usually excluding

water.

In the production of pineapple cordial in this experiment, carboxymethyl

cellulose/pectin/Arabic gum/unmodified starch was added. These substances are

hydrocolloids and they play an important role in the pineapple cordial production

since they can act as thickening agent, stabilizer, gelling agent or others which

contributed mainly to the viscosity of the cordial. Each of these substances alone has

different functions in different types of food. Despite the use of carboxymethyl

cellulose (CMC)/pectin/Arabic gum/unmodified starch, other alternative ingredients

are propylene glycol ester, other cellulose derivatives (methylcellulose,

hydroxypropylcellulose, hydroxypropyl-methylcellulose, and ethyl-methylcellulose),

other vegetable gums (alginin, guar gum, locust bean gum, and xanthan gum), and

proteins (agar, carrageenan, collagen, and gelatin). The suitability of these additives to

be used as thickening agent, stabilizer, gelling agent or others in the production of

specific food depends on their chemical properties (solubility, pH, and others) and

they are usually used in the final stage of preparations. Care must be taken so that not

to overcook the food when hydrocolloid is being used. This is because thickened and

stabilized food may burn more easily during cooking and some starches lose their

thickening, stabilizing, and gelling quality when it is cooked too long.

After all the ingredients were added, the pineapple cordial had gone through

pasteurization process which served as a preservation step to extend the shelf life of

the cordial. Since the pineapple cordial produced in this experiment was an acidic

food (pH < 4.5), the main function of the pasteurization step is to extend the shelf life

of the cordial by destruction of spoilage microorganisms (yeasts or moulds) and

inactivation of enzymes which can cause destructive effects to the cordial. As

compared to other processes, pasteurization was chosen as the preservation step

because it is a relatively mild process which usually performs below 100 °C and it

exerts only minimal changes to the sensory characteristics and nutritive values of the

pineapple cordial (Fellows, 2000).

In this experiment, the weight (whole fruit, cut fruit, juice extract, and

cordial), percentage of yield of juice extract (based on whole fruit and cut fruit), oBrix

value (juice, juice syrup mixture, and cordial), pH value (juice extract and cordial),

and percentage of yield of end product based on juice for the processing of pineapple

cordial using different hydrocolloids (pectin, xanthan gum, and CMC) were measured

and calculated. Besides, the appearance and viscosity measurement of the pineapple

cordial produced using different hydrocolloids were done for duration of three weeks.

According to the results, first of all, the weight of whole fruit, cut fruit, juice

extract and cordial produced from the pineapple was different if compared to each of

the six groups. These differences were mainly due to the degree of wastage during the

peeling, cleaning, grinding, and filtering processes of the pineapple. The results from

Group 1, 2, 3, and 5 showed significant difference between the weight of whole fruit

and cut fruit because many of the weight was lossed due to the processes mentioned

above. However, the values for weights measured were out of the concern of the

objective of this experiment which concerned on the effect of different hydrocolloids

on pineapple cordial but these values are important in determining the amount of

hydrocolloids to be used and also percentage of yield gained at the end of experiment.

Secondly, regarding the percentage of yield of juice extract based on whole

fruit, this calculated value is related to the degree of wastage during the processes

mentioned above also. Therefore, the results from Group 1, 2, 3, and 5 showed lower

values than Group 4 and 6 which obtained values of 104.76% and 86.89%

respectively. On the other hand, the percentage of yield of juice extract based on cut

fruit obtained from Group 1, 2, 3, 4, 5, and 6 were 83.20%, 85.65%, 91.74%, 98.51%,

116.36%, and 89.08% respectively. These values obtained were considered acceptable

since much of the juice was extracted from the cut fruit from the view of commercial

and economical aspects which are the very important determining factors in food

industries. It is noted that some of the percentage of yield obtained valued more than

100%. This was because during the peeling, cleaning, grinding, and filtering

processes, the water remaining on the equipments and utensils used had contributed to

the weight of the juice extract. At the same time, after the grinding process, there was

some pineapple puree left by the group before. Therefore, the weight of the juice

extract of the next group will be higher since the grinder was not washed before it was

used.

Thirdly, by observing the table of results and analysis on the oBrix value, it

was obvious that there was an increasing trend in oBrix value in the processing of

pineapple cordial from juice to cordial except for the pineapple cordial with added

pectin. This increasing trend was normal and should occur since large amount of

sugar was added in the production of pineapple cordial in order to achieve the

desirable sweetness and viscous texture. In other words, the total soluble solids are

increasing in the production of pineapple cordial from juice to cordial. However, the

un-normal trend in the pineapple cordial with added pectin was due to the

pasteurization process that might infect the thickening, stabilizing, and gelling quality

of the pectin present in the cordial. The lost of the pectin quality mentioned above

could influence the total soluble solids content in the cordial since water present in the

cordial was higher than before thus decreased the oBrix value.

Fourthly, the three average pH values of the pineapple juice extract calculated

showed fairly noticeable differences. These differences were mainly due to the degree

of maturity of the pineapple fruits used where more matured fruits had lower amount

of tartaric acids present in them and thus caused the pH to be higher. From the result,

it can be said that the pineapple fruits used by Group 1 and 2 were more matured that

those of Group 2, 3, 4, 5, and 6. However, in the production of pineapple cordial in

this experiment, the desirable pH value of the cordial was 3.5 – 4.0. This value was

achieved by all three types of cordials produced since the addition of other ingredients

may serve to decrease the pH of the cordial. The achievement of the desirable pH

range as mentioned above was important since these values of pH could serve as a

preservation method other than pasteurization by effectively inactivating the

undesirable enzymes that caused oxidative browning and inhibited the growth of

molds and yeast.

Fifthly, it was observed that the percentage of yield of the end products of the

pineapple cordials with added pectin, xanthan gum, and CMC based on juice were

higher than 100%. This was possible and normal because in the production of

pineapple cordial in this experiment, the other ingredients were added into the juice

extract that can contribute to the weight of the end product of pineapple cordials. The

main concern here is the differences between the percentages of yield of the three

types of cordials are large where the pineapple cordial with added CMC gives 47.26%

and 25.19% higher value than the pineapple cordials with added pectin and xanthan

gum respectively. The main reason is due to the amount of sugar added in order to

achieve the desired oBrix value since the amount of total soluble solids originally

present in the pineapple fruits used are different. The results indicate that the

pineapple fruits used for the production of pineapple cordial with added CMC have

low total soluble solids content.

Sixthly, in the storage study, the appearances of the three types of pineapple

cordials were almost the same for the 3 weeks of storage time. The cordials became

cloudy and also there was presence of molds and sedimentation after a week of

storage. This condition maintained for the second week of observation except for the

pineapple cordial with added xanthan gum where the black molds presented in it.

After three weeks of storage, there was formation of thin layer of black molds on the

surfaces of the three types of pineapple cordials, at the same time, sedimentation,

cloudiness, and pungent odor were developed in the three types of cordials. Generally,

the cordials were spoiled since the first week of storage. The development of molds

on the surfaces of the cordials was mainly due to contamination of the cordials and

containers during handling and insufficient pasteurization. Even the cordials are hot-

filled into the containers to destroy the heat sensitive microorganisms present in the

containers, the efficiency of the destruction of molds (thermophile) will not be high

enough since the temperature of the cordials are not high enough. Besides, during

filling process, there was presence of some air which contained spores of molds and

was flown into the containers and therefore the spores generated and caused spoilage

of the cordials. The contaminations that caused spoilage of cordials could occur easily

since the whole process of cordials production was not done in aseptic condition.

Seventhly, in the viscosity measurement of the three types of cordials, a

general trend was observed where the viscosity of the cordials decreased on the first

week of observation and increased continually on the following 2 weeks. The

viscosity changes were due to several factors including concentration, temperature

and shear strain rate in a complex manner and also dependent on the hydrocolloid(s)

and other materials present; the mixtures of hydrocolloids may act synergically to

increase viscosity or antagonistically to reduce it. Among the three types of cordials,

the pineapple cordial with added CMC always showed the highest value of viscosity

even the amount of hydrocolloid added in each of the cordial is the same. This

indicated that the thickening, stabilizing, and gelling quality of CMC was better than

the others where it had better water holding capacity thus caused higher viscosity to

the cordial. In the view of food manufacturer, CMC was more economical in the

production of cordial since lower amount (indicates lower cost) was needed to obtain

the same desired viscosity and also quality as well.

As discussed above, many potential errors could occur throughout this

experiment causing inaccuracy, low percentage of yield, wastage, and wrong

handling. Therefore, in order to avoid these errors, some precaution steps must be

taken as followed:

1. Make sure the weighing balances and pH meters are calibrated before using

them so that accurate readings can be obtained.

2. In the cutting process, make sure no wastage occur especially during removing

of the pineapple core so that the percentage of yield can be maximized.

3. Make sure the pineapple is homogenized completely using the grinder so that

accurate pH can be obtained.

4. Make sure that all of the pineapple puree is taken after the grinding process so

that maximum percentage of yield can be obtained.

5. Make sure that the Brix meter is used correctly (the window of the Brix meter

is dried completely to avoid dilution, the sample fully cover the window of the

Brix meter and facing bright or lighted area when taking the readings) to avoid

false results.

6. Make sure right proportions of ingredients are added so that accurate results

can be obtained.

7. In pasteurization process, make sure the temperature of pasteurization (88oC)

is maintained for 1 minute by adjusting the amount of heat so that over-

pasteurization can be avoided.

8. Make sure the cordial produced is hot-filled into the containers so that the heat

sensitive microorganisms present in the containers can be destroyed and

vacuum can be developed when the cordial cooled down.

9. Make sure the lids of the containers are completely covered to avoid

undesirable spoilage during storage at room temperature.

10. Make sure the appearance and viscosity of the stored cordials are checked

every week and record the findings

Conclusion:

Many types of hydrocolloids can be added in the production of pineapple or other

fruits cordials. However, different types of hydrocolloids may exert different effects

on the end product especially percentage of yield of the end product, oBrix value, pH,

viscosity, and also the storage characteristics. Therefore, the most suitable

hydrocolloid should be chose and studied before added in the cordial to obtain the

best and desired quality of the end product as well as considering the economical

factors. This experiment indicated CMC is more suitable to be used in pineapple

cordial than pectin and xanthan gum in all aspects.

References:

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pp. 231. Florida: CRC Press.

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date: 25th August 2008)

5. P J Fellows. (2000). Food Processing Technology: Principles and Practice,

Second Edition (pp. 241). Woodhead Publishing Limited.

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