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EFFECT OF HURDLE TECHNOLOGY ON BITTERNESS AND SHELF LIFE OF SWEET ORANGE (Citrus sinensis.L) JUICE

KrishiKosh

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Title EFFECT OF HURDLE TECHNOLOGY ON BITTERNESS AND SHELF LIFE OF SWEET ORANGE (Citrus sinensis.L) JUICE
 
Creator RHODA SUSESHI, P
 
Contributor UMA DEVI, K
 
Subject fruits, confectionery, fruit juices, flavouring, storage, sugar, sampling, acidity, biological phenomena, vitamins
 
Description Citrus fruits are recognized as an important component of the human diet
providing a variety of constituents important to human nutrition including vitamin C,
folic acid, potassium, flavonoids, pectin and dietary fiber, in addition to energy. Citrus
also contain significant amount of highly oxygenated terepenoid compounds
(Limonoids), particularly in underutilized by products of citrus juice production.
The sweet orange (Citrus sinensis L. Osbeck.) belongs to citrus fruits which
contributes 71% of the total citrus production in the world. India ranks 3rd in the
production of sweet orange with annual production of 4266.9 million tonnes. Fresh
juice of sweet orange is an important nutritious product providing 45 kcal, moderate
quantity of vitamin C, potassium, bioflavonoid and folic acid and essential nutrients. It
is refreshing, thirst quenching and energizing drink that improves health and meets
nutritional requirements (Syed, 2012). Fresh juice is highly appreciated as a part of
breakfast, mid morning, noon and evening beverages in all seasons, especially during
summer.
The major problem in citrus industry is the formation of bitterness in the citrus
juice within hours of juice extraction from the fruit or if heated within a few minutes.
This is called “delayed bitterness”. The primary causes of delayed bitterness are the
triterpenoid dilactones, limonin and nomilin. The study, “Effect of hurdle technology on
bitterness and shelf life of sweet orange (citrus sinensis.L) juice” was planned with an
objective to reduce the bitterness and extend the shelf life of sweet orange juice in its
fresh plain form, retaining its natural taste and flavour. Hurdle technology in this work
is a method of ensuring that changes in sweet orange juice are eliminated or controlled
so that the juice is safe for consumption, and its shelf life is extended. The hurdles in a
food system are high temperature during processing, low temperature during storage,
increasing the acidity, lowering the water activity and addition of sugar, salt or
preservatives. To delay formation of bitterness and retain the fresh flavour, taste and
mild acidity of the fresh sweet orange juice for a period of few hours at ambient
temperature to a few days at low temperatures, small quantities of sugar, salt and
preservative were added separately and tested for acceptability and physic chemical and
microbial characteristics. Irradiation was another hurdle used on plain sweet orange
juice and on samples added with sugar or salt packed in two materials, HDPE pouches
and glass bottles and subjected to four doses of irradiation, 0.25, 0.50, 0.75 and
1.00kGy.
Samples were analyzed for physicochemical properties (pH, TSS, titrable acidity,
reducing sugars and vitamin C,) and microbial tests. Sensory evaluation was done using
hedonic scale with 5 point continuum for evaluating the acceptability by taste panel
judges.
Sweet orange juice was packed in HDPE pouches in six different formulatins
i.e., T1 (plain sweet orange juice), T2 (plain sweet orange juice + sugar), T3 (plain sweet
orange juice + salt), T4 (plain sweet orange juice + potassium sorbate), T5 (plain sweet
orange juice + sugar + potassium sorbate), T6 (plain sweet orange juice + salt +
potassium sorbate).These samples were stored at ambient temperature, at 6-9°C and at -
20°C.
Sensory evaluation of samples kept at ambient temperature and at 6-9°C tested
every two hours to estimate at which hour the bitterness has developed showed that at
ambient temperature bitterness developed at 5th hour after squeezing the juice and at 9th
hour in juice stored at 6-9°C.
Physicochemical analysis of sweet orange juice samples with hurdle materials,
sugar, salt, preservative before and after irradiation at four doses showed that the pH of
the juice decreased in both HDPE pouches and glass bottles. The titrable acidity did not
change due to the effect of the irradiation doses. There was a slight increase and
decrease in the acidity values. The increase and the decrease in the acidity values were
statistically not significant. There was a slight decrease in the reducing sugars but the
decrease was statistically not significant. There was very slight decrease in the Vitamin
C as the irradiation dose increased to 0.5kGy; 0.75kGy and 1.00kGy.
The juice kept in HDPE pouches and stored at -20°C and studied for shelf life
for 15 days with an interval of 5 days revealed that, pH of the sweet orange juice
decreased as the storage period increased from 0th day to 15th day. TSS of sweet orange
juice samples with and with hurdle materials gradually increased from 0th day to 15th
day. The increase was significant (P
 
Date 2016-06-22T15:03:11Z
2016-06-22T15:03:11Z
2013
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/67740
 
Language en
 
Relation D9432;
 
Format application/pdf
 
Publisher ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY