Effect of Pasteurization Temperature on Quality of Aonla Juice During Storage

Effect of Pasteurization Temperature on Quality of Aonla Juice During Storage

 

The aonla fruit or Indian gooseberry comes from a small to medium size deciduous tree

native to India and contains 500 to 700 mg. of ascorbic acid per 100 g. of pulp, making it

one of the richest sources of Vitamin C. Aonla is highly nutritious and has therapeutic

qualities for treating the common cold, headaches and gastric troubles.[1] However, it has

limited table value because of its sour and astringent taste, but the fruits are processed

into products like preserves, candy pickles and juices.[2]

 

Aonla juice is one of those derivative liquids that contain plenty of micronutrients and

phytochemicals that enhance human function, structure and physiology and is promoted

to cure such medical conditions as high blood pressure and cholesterol levels and

rheumatism.[3]

 

Pasteurization refers to a process of heating liquid or solid food to a certain temperature

for a specific length of time and then immediately cooling the same, which would effect

the slowing of microbial growth in the food. The process aims to reduce the number of

pathogenic micro-organisms in the food to render them unlikely to cause disease.[4]

 

Flash pasteurization is the process of heating perishable beverages like fruit and

vegetable juices before putting them into containers in order to increase safety against

spoilage microorganisms and extend their shelf life, but must be used alongside sterile

fill technology. The process maintains better color and flavor in juices than other kinds

of pasteurization.[5] Flash pasteurization is the best preserver for berry juices and the

recommended temperatures are 80 degrees Centigrade or higher for 30 seconds.

The juice must fill bottles or cans to the fullest, after which the containers must be

 immediately closed and cooled. Since juices high in nitrates affect some enamels in

 cans, the latter need special enamel lining.[6]

 

Fruit juices are commonly prepared by squeezing or macerating fresh fruits without

applying heat or solvent.[7] Fruit  juices deteriorate because of naturally occurring

enzyme activity, which makes the juice settle out and acid tolerant yeasts to grow,

leading to fermentation. To prevent these, the right temperature and duration of

heating must be established during pasteurization. The continuous rapid heating and

cooling of the juice must be closely controlled to produce juices efficiently, with

minimum loss of quality.[8]

 

The heat treatment in flash pasteurization minimizes flavor changes and is best fitted

for premium quality and natural-style juices. The economical aseptic packaging of

juices in flexible laminated multilayer plastic containers has been widely used globally

because the product can be stored at ambient temperature. In this case, the juice must

be heat pressurized, cooled and put into a pre-sterilized package under sterile

conditions. Such aseptically packaged juices placed at room temperature have 12

months of shelf-life.[9]

 

The use of common chemical preservatives like the potassium and sodium salts of

sorbic, benzoic and sulfurous acids in pure fruit juices is no longer widely permitted,

although a product with a juice drink label may allow preservative use in non-aseptic

packaging. Freezing can also preserve fruit juices, particularly in the transport and

storage of concentrated juices.[10]

However, based on a study, the pasteurization treatment also kills off the beneficial

bacteria in juices, alters the juices’ natural consistency when it separates its water and

sugar content and can compromise its nutritional value when it breaks down its

nutrients.

 

[1] Chhattisgarh State Medicinal Plant Board, “Pilot Project Proposal on Mission Aonla”, pdf,

<http://cgvanoushadhi.gov.in/anola.pdf>  [accessed 12 May 2010]

[2] R. K. Goyal et al, “Osmotic Dehydration of Aonla”, World Scientific eProceedings, pdf abstract, 2011

<http://eproceedings.worldscinet.com/9789812771957/9789812771957_0153.html>

[accessed 12 May 2011]

[3] “Cure-All Juices: Indian Gooseberry (Amalaki)”, The Free Library, 2008,

<http://www.thefreelibrary.com/Cure-All+Juices%3a+Indian+Gooseberry+%28Amalaki%29-a01611725429> [accessed 12 May 2011]

[4] Sokoya Oluwatomi Temitayo, “Pasteurization in Fruit Juice”, OPPAPERS.COM, September 2010,

<http://www.oppapers.com/essays/Pasterization-In-Fruit-Juice/424026>  [accessed 12 May 2010]

[5] “Flash Pasteurization”, Wikipedia, 8 March 2011, <http://en.wikipedia.org/wiki/Flash_pasteurization>

[accessed 12 May 2011]

[6] “Principles and Practices of Small- and Medium-Scale Fruit Juice Processing”,

FAO Corporate Document Repository, pdf, <http://www.fao.org/docrep/005/Y2515E/y2515e16.htm#P113_9960>  [accessed 12 May 2011]

[7] “Juice”, Wikipedia, 9 May 2011, <http://en.wikipedia.org/wiki/Juice>  [accessed 12 May 2011]

[8] “Tubular Pasteurizer for Fruit Juice”, Food and Nutrition Library,

<http://www.greenstone.org/greenstone3/nzdl?a=d&d=HASH011c1af96100e23ee05d58e7.7&c=fnl&sib=1&dt=&ec=&et=&p.a=b&p.s=ClassifierBrowse&p.sa=>  [accessed 12 May 2011]

[9] “Fruit Juices”, Scribd, <http://www.scribd.com/doc/30116533/Fruit-Juices>  [accessed 12 May 2011]

[10] ibid

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