Experimental investigations of cryogenic and conventional grinding on cumin seed and coriander seed

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International Journal on Theoretical and Applied Research in Mechanical Engineering (IJTARME)

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ISSN (Print): 2319-3182, Volume -6, Issue-3, 2017 7

Experimental investigations of cryogenic and conventional grinding on cumin seed and coriander seed

1Rohinee M. Barai, ²Anjali D. Kadam, ³Ajit V. Harde

1,2,3

Mech. Engg. Department, Priyadarshini J.L. College of Engineering, Nagpur, India

Abstract-The fat content of spices poses problem of temperature rise. Due to this temperature rise, spices lose a significant fraction of their volatile oil or flavouring components. Therefore a cryogenic grinding system was designed and developed to cool the spices before feeding to the grinder and also maintain the cryogenic temperature in the grinding zone. The main components of the cryogenic grinding system are a precooling jar and grinder. A commercially available grinder was adopted for this purpose.

The test conducted on grinding of cumin seed and coriander seed. In this project varying the different properties of spices under ambient and low temperature conditions. Various factors i.e. moisture content, volatile oil, non-volatile ether extract, affect the product quality of the spices.

Experimental investigations of sample spices, Quality testing and comparison between conventional grinding and cryogenic grinding system. The results show the loss of volatile oil, Non volatile ether extract can achieved by cryogenic grinding system.

Keywords :- conventional grinding, cumin seed, corinder seed, cryogenic grinding, volatile oil.

I. INTRODUCTION

The main aim of spice grinding at low temperature is to obtain good product quality of the spices in terms of flavour & colors. Varying the different properties of spices under ambient and low temperature condition.

Various factor i.e. moisture content, volatile oil, non- volatile ether extract, piprine content and curcuminoid content affect the product quality of the spices.

Experimental investigations of sample spices. Quality testing, comparison between conventional grinding and cryogenic grinding for spices.

Indian, spices, with the export of 1, 50, 845 tons valued of Rs. 900.60 crore, are another major food commodity.

A large part of this is exported as ground spice. The grinding heats thus high temperature during grinding process is the major reason for loss of flavour and aroma of the ground spices.

Reduction of high temperature by means of conventional has not helped much. Cryo- grinding appears to be a viable technique for retention flavour and quality. Also there is reduction in grinding energy and maintain the

uniformity in the particle sizes.

In the normal grinding process heat is generated when energy is used to fracture a particle into a smaller size.

This generated heat usually is detrimental to the product and result in some loss of flavour and quality. During grinding the temperature of the product rises to a level in the range of 42-950c which varies with the oil and moisture content of the spices, but spices lose a significant fraction of their volatile oil or flavoring components due to this temperature rise.

The temperature rise of the product can be minimized to some extent by circulating cold air or water around the grinder. But this technique is not sufficient to significantly reduce the temperature rise of product. The loss of volatile oil can be significantly, reduce by a cryogenic grinding technique.

In the 19th century spice were eagerly sought and the wealth and power of nations were involved in the control of the spice trade Despite their economic importance in the world trade ( worth $ 1.5 billion), they have not received the attention they so richly deserve, notably in their processing and quality aspects value added product such as ground spices, mixes, oleoresins and spice oil extract have vast industrial applications and with improvements in processing could improve their share in the market.

II. EXPERIMENTAL SET UP

Fig 4.1 Schematic of Experiment Set Up (1) Thermocouple for temperature measurement of

grinding spices sample (2) Grinding Jar

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(3) Spice sample

(4) Thermocole insulation (5) Liquid nitrogen in

(6) Thermocouples for temp. measurement before grinding of sample

(7) Thermocole Insulation (8) Liquid Nitrogen Gas out

III. EXPERIMENTATION

EXPERIMENTATION ON DIFFERENT SAMPLE

Table 1 Time temperature study of spices grinding at atmospheric temperature

Spices Weight (gm) Time (sec) Temp. before

grinding, (K)

Temp. after grinding, (K)

Temp. Rise (K)

Cumin seed 125 165 305.5 320.5 15.0

Coriander seed 125 270 306.3 334.5 18.2

Table 2 Time temperature study of spices grinding at cryogenic temperature

Spices Weight

(gm)

Time (sec)

Temperature in precooling jar (K)

Temperature In grinder before grinding (K)

Temperature in grinder after grinding (K)

Rise in temp.

(K)

Cumin seed 125 165 128.0 256.0 276.5 20.5

Coriander seed 125 270 128.0 243.0 301.2 58.2

Table 3 Moisture content for conventional and cryogrinding of spices

Spices Weight

(gm)

Moisture content (%) For conventional grinding

Moisture content (%) for cryogrinding

% decrease

Cumin seed 125 7.41 6.6 10.93

Coriander seed 125 6.94 6.45 7.00

Table 4 Volatile oil content for conventional and cryogrinding of spices

Spices Weight

(gm)

Volatile oil content (%) for conventional grinding

Volatile oil content (%) for cryogenic grinding

% Increase

Cumin seed 125 3.0 4.8 43.3

Coriander seed 125 1.1 3.0 172.7

Table 5 Non Volatile ether extract content for conventional and cryogrinding of spices

Spices Weight

(gm)

Volatile oil content (%) for conventional grinding

Volatile oil content (%) for cryogenic grinding

% Increase

Cumin seed 125 14.32 29.75 107.7

Coriander seed 125 14.44 21.00 45.4

“Fig. 1 variation of moisture content % in conventional

& cryogenic grinding system”

Fig.1 shows the variation of moisture content % in ambient and cryogenic grinding. It is observed that the moisture content % is less in all sample spices in cryogenic grinding than in conventional grinding.

“Fig.2 variation of volatile oil content % in conventional

& cryogenic grinding system”

Fig.2 shows the variation of volatile oil % in conventional and cryogenic grinding. It is observed that the volatile oil % is more in all sample spices in cryogenic grinding than in conventional grinding.

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“Fig.3 variation of non volatile oil % in conventional &

cryogenic grinding system”

Fig.3 shows the variation of non -volatile ether extract

% in conventional and cryogenic grinding. It is observed that the non- volatile ether extract % is more in all sample species in cryogenic grinding than in conventional grinding.

IV. RESULT AND DISCUSSION

Testing of ground samples were carried out at Premier Agmark Laboratory, Nagpur. Tables 1 & 2 show the time temperature study for cumin seed and corinder seed during conventional grinding and cryogrinding for the same weight of samples. The quality characteristics of ground spices were found out by considering the properties, moisture content %, volatile oil content %, non- volatile ether extracts %, Table 3 shows the moisture content comparison for conventional and cryogrinding of spices. Sample spices, cumin seed shows the moisture content decrease by10.93%, whereas in coriander seed it found decrease by 7%. Table 4 shows the volatile oil content for conventional and cryogrinding of spices. Volatile oil content for cumin seed is increased by 43.3% and for coriander seed is increased by 172.7% compared to conventional grinding. Table 5 shows the non-volatile ether extract for conventional and cryogrinding of spices. Non-volatile ether extract for cumin seed is increased by 107.7 % and for corinder seed is increased by 45.4% compared to conventional grinding.

From this it is concluded that loss of quality & flavour can be achieved by cryogenic grinding technique.

REFERENCES

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[10] “General Grading and marking Rules” means the General Grading and Marking Rules, 1988 made under section 3 of the Agricultural produce ( Grading and Marking ) Act, 1937 ( 1 of 1937);

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