Masih berhubungan dengan skripsi, kali ini saya menge-post salah satu objek penelitian yang saya gunakan sebelum akhirnya berganti judul, yaitu tentang pomegranate atau yang lebih kita kenal dengan buah delima. Masih ingat pada saat itu buah ini sulit sekali didapatkan. Saya sudah mendatangi setiap toko buah besar maupun kecil tapi hasilnya nihil. Akhirnya penelitian mengenai buah ini pun dibatalkan. Berikut ini adalah review mengenai buah delima atau pome.
Pomegranate is ornamental plant in tropical and subtropical area which can grow up to 12 feet tall. Pomegranate is tolerant to heat and moderately acid to slightly alkaline soil. Pomegranate is round in shape with diameter between 5 to 8 cm. There are many varieties of pomegranate with different qualify in nutrient contents and appearance. These varieties have a range of quality varying from very sweet to very acid. Generally, the rind is smooth but leathery with yellow, orange or red in colour. The juice colour within the aril varies from light pink to dark red, sometimes yellow and clear appearance might be found in some cultivars. The red aril of pomegranate juice is the most popular variety for food product.
Pomegranate is classified as berry which consist of packed arils and irregular segments that are separated by non-edible white piths and thin membranes. Each aril contains a seed which surrounded by edible juicy pulp. The seeds are classified as soft to hard seeds depending on their varieties. The seeds appearance and the balance of sugar and acid content affect the pomegranate quality.
Pomegranate contains substantial amount of antioxidant compounds which are mostly polyphenols compounds that are found in rind and arils. Recently, many researchers are interested to investigate polyphenols compounds in pomegranate rind and arils. Anthocyanins, ellagic acid derivatives, and hydrolyzable tannins were found in pomegranate juice.
Processing methods might affect the quality of pomegranate juice. There was a study about pomegranate juice from Izmir (Turkey) cultivar which was clarified and pasteurised using various techniques. Pomegranate juice was clarified by using ultrafiltration, conventional finning, combination between conventional finning and PVPP (polyvinylpolypyrrolidone), respectively. The pomegranate juice was then packed in bottle and pasteurised for 20 minutes in boiling water. The result showed that clarification methods and heat treatment significantly affected pomegranate juice colour and total phenolic compounds. Reduction of total phenolic compounds in pomegranate juice were performed as 14% on ultrafiltration, 1.2% on conventional fining with PVPP (polyvinylpolypyrrolidone), and 2.3% on conventional fining method.
The loss of ascorbic acid from pomegranate juice increased along with temperature and time of processing. Approximately, 69% of vitamin C was retained after processing at 70oC for 90 minutes. The result also showed that 90% of total phenolic compounds was retained after processing at 70oC for 90 minutes.
Alper, N.H., Bahceci, K.S., Acar, J. 2005. Influence of processing and pasteurisation on colour values and total phenolic compounds of pomegranate juice. J Food Process Pres 29: 357-368.
Gill, M.I., Barberan, F.A.T., Pierce, B.H., Holcroft, D.M., Kader, A.A. 2000. Antioxidant activity of pomegranate juice and its relationship with phenolic composition and processing. J Agri Food Chem. 48:4581-4589.
Maclean, D., Karina, M., Harald, S., Dan, H. 2011. Pomegranate production. Georgia: University of Georgia. (online). http://www.caes.uga.edu/ publications/displayPDF.cfm?pk_ID=7912 (26 Des 2012).
Paul, R. and Ghosh, U. 2012. Effect of termal treatment on ascorbic acid content of pomegranate juice. Indian J Biot 11: 309-313.
Still, D.W. 2006. Pomegranates: A botanical perspective. In N.P. Seeram, R.N. Schulman & D. Heber, Pomegranates : ancient roots to modern medicine, (pp. 199-209). New York: CRC Press.