Nutritional composition of Raw and Roasted Garden Cress Seed ( Lepidium sativum L . ) Flour

Background: Garden cress is one of the traditional medicinal plants packed with nutrients. In India, garden cress seeds are consumed either raw or in processed forms. The different processes employed such as roasting may provide palatability, acceptable colour, and texture and raise the nutritional composition. Methods: The present study was conducted to assess the nutritional composition of raw and roasted garden cress seed flour. Raw garden cress seed flour was developed by drying the seeds in oven at 60 0 C for 45 minutes, followed by grinding and sieving through 60 mesh sieve. Roasted flour was developed by initial roasting of seeds in iron vessel followed by similar procedure as for raw flour. Both flours were stored in air tight containers for further research analysis. In nutritional composition moisture, total ash, crude protein, crude fat, crude fibre, total carbohydrate and physiological energy were assessed for both raw and roasted seed flour. Results: The result of the nutritional composition for raw and roasted seed flour showed that roasted flour has a higher nutritional composition than raw seed flour. It can be concluded that processing not only improves the shelf life and acceptability but also improves the nutritional composition of flour, which can be helpful to maintain and improve health and nutritional status.


Crude fat
Crude fat estimation is based on the principle that weighed and dried sample is placed in a cellulose thimble and continuously extracted with petroleum ether for about 90 minutes in a soxhlet assembly. The ether is evaporated from the flask at the end of the extraction period, leaving an oil residue. The fat content is calculated by weighing the flask before and after extraction and comparing the difference to the weight of the original dry sample.

Procedure
For this, 2g of moisture free sample was transferred to an extraction thimble. The beaker was washed thoroughly and put in hot air oven at 60 0 C for drying and weighed after cooling. The sample in extraction thimble was plugged with fat free absorbent cotton. Then, 100 ml of petroleum ether was put into the beaker. The beakers were packed into the system and temperature was set to 90 0 C in the system. The extraction was carried out for one hour at 90 0 C. The temperature was raised to 110 0 C after the completion of extraction period and the stopper was closed in the solvent compartment to collect the solvent. The beaker was removed along

Crude protein
Crude protein estimation is based on the principle that sample is digested with boiling sulphuric acid. The nitrogen of sample converted to ammonium sulphate is made to react with strong alkali. The released ammonia is collected into boric acid solution, titrated with standard sulphuric acid and used to calculate the nitrogen content of sample.

Procedure
Crude protein was determined by using the principle of micro Kjeldahl method AOAC (2010) using automatic Kel-Plus Classic-dx apparatus. In this, finely ground and moisture free 0.5 gram sample was taken in pre dried digestion tubes in triplicate followed by addition of 10 ml of conc. sulphuric acid and 3 gram of digestion mixture. Tubes were transferred into the digestion unit and heated at 420 0 C for about 90 minutes or till the colourless or light bluish contents of tubes obtained. After completion of digestion, samples were cooled to room temperature and distilled in distillation unit. During distillation, released ammonia was collected in a 4 per cent boric acid solution containing mixed indicator. Boric acid containing ammonia was then titrated against 0.1N HCl till the end point of light pink colour change was attained. A blank sample was also prepared, and titrated with 0.1N HCl. A factor of 6.25 was used to assess the quantity of crude protein from the amount of nitrogen measured. The quantity of crude protein was calculated using this formula: Normality × 100 × 14 × Titrate volume (S-B)× F Crude protein (%) = Sample weight × 1000 Where, S=Volume (ml) of HCl (N/10) used in titration of sample B=Volume (ml) of HCl (N/10) used in titration of blank F=Factor for converting nitrogen to protein i.e. 6.25

Crude fibre
Crude fibre was determined as the organic residue, which remains after the defatted material that boiled successively with diluted sulphuric acid and dilutes sodium hydroxide solution.

Procedure
In a 600 ml beaker, 2 g weighed defatted sample and 200 ml of 1.25 percent boiling sulphuric acid were added. Beaker was covered with condenser flask and boiled for 30 minutes. The loss in volume was made up with water. The mixture was filtered with whatman no. 54 filter paper using buchners funnel and flask with gentle suction. With 100ml hot distilled water residue was washed back in beaker followed by addition of 1.25% sodium hydroxide solution and boiling for 30 minutes. Meanwhile, whatman no. 54 filter paper was cut as per size of funnel and placed in weighing bottle and dried for an hour at 105 0 C. Through weighed filter paper, solution was filtered and any residue from the sides of beaker was washed, using hot distilled water into filter paper. Then, allowed to drain, transferred to oven and dried at 105 0 C for 3 hours and weighed.

Total ash
The ash content is determined by charring a known weight of sample at 550 0 C until all carbon is burnt. The remaining residue is ash, which signifies the sample's inorganic contents.

Procedure
Moisture free sample was taken to analyze ash. Five gram sample was taken in dried, weighed crucibles and charred over low bunsen flame. Crucibles were kept in muffle furnace at 550 0 C until a white ash was obtained. Thereafter, the crucibles were removed from muffle furnace and cooled in a desiccator and reweighed. Ash content was calculated using given formula:

RESULT AND DISCUSSION
The present study was performed to assess proximate composition of raw and roasted garden cress seeds flour. In proximate composition moisture, total ash, crude fat, crude protein, crude fiber, total carbohydrate and physiological energy of flours were assessed. Results of proximate composition showed increase in contents of crude protein, total ash and total carbohydrates whereas the decrease in content of moisture and fat were observed on roasting.

Proximate composition
The data in respect of proximate of raw and roasted garden cress seed flour have been presented in Table 1.

Moisture content
The moisture content of raw and roasted garden cress seeds was 6.25 and 4.89 per cent, respectively. The result of moisture was confirmed by the results obtained previously by Toliba

Ash content
The data obtained revealed that the ash content of raw garden cress seed flour was 4.89 percent that was 5.12 percent in roasted seed flour. The result of ash of raw garden cress seed flour was confirmed by the results obtained previously by Toliba and Mohmed (2019) and Hassan and Rahman (2019). Ash content of flour directly related to the amount of minerals. The higher ash content in raw and roasted GCS flour indicated that the garden cress seeds flour is a good source of minerals.

Protein content
In case of protein, observed data showed that the raw garden cress seed flour had 23.90 percent protein which was 24.62 percent in roasted flour. The results of protein content of raw garden cress seed flour was almost in agreement with that documented by Gaafar Roasting technique increases the protein content of garden cress seeds, which may be due to the release of protein from the proteiniron-phytate complex during roasting.

Fat content
The value obtained for fat content of raw and roasted garden cress seed flour revealed that seeds contained 12.68 and 12.

Total carbohydrate
The total carbohydrates in raw garden cress seeds flour that was calculated by difference method in which total amount of moisture, ash, fat, fiber and protein was substracted from 100. The total carbohydrate content of raw and roasted garden cress seeds flour was 44. 19  Values are mean ± SD of three independent replications NS-Non significant, **-significant at 1 percent, *-significant at 5 percent