Development of Sweet Lime Powder and Its Chemical Chemical Analysis

Abstract

Studies were conducted for on development of Sweet lime peel powder and chemical properties of Sweet lime peel powder were investigated. Sweet lime is a greenish orange in colour and its flesh is pale yellow in colour. The sweet lime peel powder was dried in a Tray dryer at 55ºC temperature. The dried sweet lime peels were ground using a pulveriser. The average particle size of sweet lime peel powder prepared by pulveriser was found 0.243 mm. The chemical properties of sweet lime peel powder such as moisture content, pH, citric acid, crude fat, crude fibre, protein, carbohydrates, calcium and iron were 4.1 %, 5.3, 1.8%, 0.14 %, 8.48 %, 1.69 %, 28.42 %, 153.22 mg/100 gm and 0.80 mg/100 gm respectively.

KEYWORDS: Sweet lime, Peel, Drying, Particle size, and Chemical properties.

Introduction

Citrus is an ancient crop, with records of human cultivation extending back to at least 2100 BC. The sub-genus Citrus (Swingle), family Rutaceae and subfamily Aurantioideae are of three types Citrus, Fortunella (Kumquat) and Poncirus Trifoliata. Sweet lime is known as Mousambi in India, and its scientific name is Citrus limetta. Its skin is greenish orange in colour and its flesh is pale yellow in colour. Sweet lime popular indigenous citrus fruit relished for its cooling and therapeutic effect. It also contains citric acid, sugar, and certain minerals like calcium and phosphorus. In the traditional indigenous medicinal system, sweet lime juice is valued for curing fever, malaria and jaundice Vitamin C as a primary component of the lime juice increases the resistance of individuals to several diseases.

Sweet lime peels are considered to be one of the potential sources for the screening of anticancer, antimicrobial, antioxidant, and free radical scavenging agents in the Mediterranean region the peel is chewed to sweeten the breath. Citrus limetta peels are rich in pectin which is known to possess blood sugar-lowering and cholesterol-lowering properties. Waste materials such as peels and seeds obtained from post-harvest management are rich sources of biologically active possessing various physiological functions. Considering all the important medicinal values of sweet lime peel, the study was conducted.

Materials and Methods

Preparation of sweet lime peel powder

Sweet lime peels were obtained after extraction of juice from sweet lime fruit then dried in a hot air oven at 55°C. A pulveriser was used to make the powder from peel and a sieve was used to obtain a fine powder.

Determination of particle size of sweet lime peel powder

Different sizes (mesh) of sieves were used to determine the particle size. A known quantity of the sweet lime peel powder sample (500 g) was placed in the top sieve and sieves were shaken for 10 min in the power-operated sieve shaker. Average particle size was calculated by using the following equation;

Average particle size = 0.135 (1.366) FM

Chemical properties of sweet lime peel powder

Moisture content

The moisture content of the sweet lemon peel powder was determined by the standard hot air oven method. pH of the sweet lime peel powder is measured by the pH meter. 5 g of test sample were taken into the flask. 100 ml of distilled water is added into the flask and shake it for one minute. The flask is allowed to settle for one hour. Measured the pH value.

Citric acid

1 gm of dried sweet lime peel powder was taken. 20 ml distilled water was added into dried peel powder. Pipette out 1 ml of the sample in a conical flask and 100 ml distilled water was added to it. 2 to 3 drops of phenolphthalein indicator were added to it. The solution was titrated with 0.1 N NaOH. The endpoint is faint pink colour. Citric acid was calculated by using the following equation.

Crude fat

5 gm peel powder was weighed accurately and transferred to the thimble and defatted with petroleum ether in Soxhilate reflux apparatus for 6-8 hrs at 80°C. The residue was procured and ether is removed by evaporation. The loss in weight of the thimble was estimated as loss of lipids from the sample and expressed as per cent lipids in the sample. The crude fat was calculated by using the following formula AOAC.

Crude fibre

Determination was carried out by taking 3 gm sweet lime peel powder and digesting first with 1.25% H2SO4, then it was washed with distilled water and filtered, then it was again digested with 1.25% NaOH solution then filtered the digested solution into the other flask. Then sample residue was ignited by placing the digested samples in a muffle furnace maintained for 3-5 hrs at a temperature of 550 - 650 °C till grey or white ash was obtained. The percentage of crude fibre for the sensory accepted sample was calculated by using the AOAC method AOAC.

Protein

2 gm sweet lime peel powder sample was weighed and put into the digestion tube. 20 ml concentrated Sulphuric acid (98%) and 2 tablets of digestion mixture as catalyst was added into the digestion tube. The digestion was carried out for 3-4 hrs (till the digested contents attained transparent colour). The digested material was allowed to cool at room temperature and diluted to a final volume of 50 ml. The ammonia trapped in H2SO4 was liberated by adding 40% NaOH solution through distillation and collected in a flask containing 4% boric acid solution, possessing methyl indicator and titrated against standard 0.1 N H2SO4 solutions. The factors 6.25 and 5.70 were used for the conversion of per cent nitrogen into crude protein contents of composite flours. The nitrogen content and hence the protein content was calculated using the formula below AOAC (1995).

1 Ml of 1 N H2SO4 = 14 mg Protein (%) = N2 (%) × 6.25

Carbohydrate

Carbohydrate content was calculated for sweet lime peel powder by using the following formula given in AOAC (2005).

Total carbohydrate = 100 – (moisture + fat + fibre + ash + protein)

Calcium

Calcium content was estimated by the O-cresolphthalein Complexone (OCPC) Method, Endpoint assay. OCPC combines with calcium at alkaline pH to form a purple colour complex, the absorbance of which is measured at 578 nm. The recommended volumes of kit reagents (Coral Clinical System, India) were added to the test tubes labelled as Blank, Standard and Test. The reaction mixture was incubated at room temperature for 5 min. followed by measurement of absorbance at 578 nm. The concentration of calcium in mg/dl was determined by the following formula:

Calcium in mg/dl = [Absorbance of Test/ Absorbance of Standard] X 10

Iron

Determination of Iron was done by the Ferrozine method where the Fe (II) ions react with Ferrozine to form a violet-coloured complex. The recommended volumes of kit reagents (Coral Clinical System, India) buffer solution, colour reagent and the standard solution were added to the test tubes labelled as Blank, Standard and Test. The reaction mixture was incubated at room temperature for 5 min followed by a measurement of absorbance at 578 nm. The concentration of iron in the samples was determined by the following formula.

Iron (μM) = [Absorbance of Test/ Absorbance of Standard] X 35.8

Result and Discussion

• Drying of sweet lime peel:

The drying time taken to drying the sweet lemon peel powder at 55 °C was 17 hrs.

• Particle size analysis using standard sieve method:

The particle size of the sweet lemon peel powder was less than 0.243 mm.

• Chemical analysis of sweet lime peel powder:

The following chemical property has been determined.

Conclusion

This study suggested that the sweet lime peel powder could be used for value addition in many products viz; bakery, juice, glucose, etc.

References

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