Main Article Content

Abstract

Abstract

Moisture sorption isotherms have an important role in the quantitative approach to predict shelf life of the food due to their sensitivity to moisture changes. The objectives of this research were to determine the equilibrium moisturecontent ofparboiled rice,to findthe bestmodel todescribe thesorption isotherm curve ofparboiled rice, and to predict shelf-life of the parboiled rice during storage. Moisture sorption isotherms of parboiled rice were determined using the standard gravimetric static methodat temperature of 30o, which involves the use saturated salt solution to maintain a fixed equilibrium relative humidity. To achieve different relative humidity environments, aqueous solutions of NaOH, MgCl2, Mg(NO3)2, KI, NaCl, KCl, Na2SO4, and NH4H2PO4 to have relative humidity of 7%, 33%, 52%, 69%, 75%, 84%, 87% dan 92%. Five gram samples of parboiled rice were stored in dessicators. The samples were weighed periodically until they constant. The Hasley, Oswin, Henderson, Chen-Clayton and Caurie models were applied to describe the relationship between equilibrium moisture content and relative humidity. The mean relative deviation was used to evaluate the goodness of each models. The result showed that equilibrium moisture content of parboiled rice fromrelative humidity of 7%, 33%,52%,69%, 75%, 84%, 87% dan 92% respective of 6.93% dry basis (db), 11.09%db, 14.22% db, 15.86% db, 17.05% db, 19.68% db, 23.92% db, dan 25.59% db. Water sorption isotherm parboiled rice had sigmoid shape. The Oswin model was found to be the best model to describe the experimental sorption data for parboiled rice was the value MRD is 3.85 and R2 is 0.98. Parboiled rice packaged with HDPE, LDPE, and PP have a predict shelf-life respective of 2.2, 2.3 and 8.8 year.

Abstrak
Sorpsi isotermi memiliki peran penting dalam pendekatan kuantitatif untuk menduga umur simpan bahan yang rentan terhadap perubahan kelembaban. Tujuan dari penelitian ini adalah untuk menentukan kadar air kesetimbangan beras pratanak, menentukan model yang tepat dalam mendeskripsikan pola kurva sorpsi isotermi beras pratanak, dan memprediksikan umur simpan beras pratanak dengan metode kadar air kritis. Sorpsi isotermi beras pratanak ditentukan dengan menggunakan metode gravimetri statis pada suhu 30o, dengan menggunakan larutan garam jenuh untuk mengatur kelembapan relatif. Untuk mencapai lingkungan kelembaban relatif yang berbeda, larutan NaOH, MgCl2, Mg(NO3)2, KI, NaCl, KCl, Na2SO4, dan NH4H2PO4 dengan kelembaban relatif berturut turut7%,33%,52%,69%,75%,84%, 87%dan92%.Limagramsampel beraspratanakdisimpandalam desikator. Sampel ditimbang secara berkala hingga mencapai berat konstan.Model Hasley, Oswin, Henderson, Chen-Clayton dan Caurie diterapkan untuk menggambarkan hubungan antara kadar air kesetimbangan dan kelembaban relatif. Mean Relative Determination digunakan untuk mengevaluasi ketepatan masing-masing model. Hasil penelitian menunjukkan bahwa kadar air kesetimbangan beras pratanak pada RH 7%, 33%, 52%, 69%, 75%, 84%, 87% dan 92% berturut-turut adalah 6.93% bk, 11.09% bk, 14.22% bk, 15.86%bk, 17.05% bk, 19.68% bk, 23.92% bk, dan 25.59% bk. Kurva sorpsi isotermi beras pratanak memiliki bentuk sigmoid. Model Oswinadalah model yang paling tepat dalam menggambarkan sorpsi isotermi beras pratanak dengan nilai MRD sebesar 3.85 dan R2sebesar 0.98. Beras pratanak yang dikemas dengan HDPE, LDPE, dan PP memiliki umur simpan berturut 2.2 tahun, 2.3 tahun dan 8.8 tahun.

Keywords

Modeling parboiled rice shelf-life sorption isotherm

Article Details

Author Biographies

Hasniar ., Institut Pertanian Bogor

Program studi Teknologi Pascapanen, Departemen Teknik Mesin dan Biosistem, Institut Pertanian Bogor

I Wayan Astika, Institut Pertanian Bogor.

Departemen Teknik Mesin dan Biosistem, Institut Pertanian Bogor.

References

  1. [AOAC] Association of Official Analytical Chemist.
  2. 2005. Official Methods of Analysis, 18th edn.
  3. AOAC, Inc. Washington DC.
  4. [SNI] Standar Nasional Indonesia. 1992. Cara
  5. uji makanan dan minuman. SNI 01-2891-
  6. 1992. Pusat Standar Industri. Departemen
  7. Perindustrian.
  8. Augustin, I.S., S. Franceschi, D.J.A. Jenkins, C.W.C.
  9. Kendall, and C. La Vecchia. 2002. Glycemic
  10. index in chronic disease: a review. European
  11. Journal of Clinical Nutrition. 56: 1049-1071.
  12. Ayamdoo, J.A., B. Demuyakor, W. Dogbe, and
  13. R. Owusu. 2013. Parboiling of paddy rice,
  14. the science and perception of it as practiced
  15. in Northern Ghana. International Journal of
  16. Scientific and Technology Research. 2(4): 13-
  17. 18.
  18. Dors, G.C., Vd.S. Bierhals, and E. Badiale-Furlong.
  19. 2011. Parboiled rice: chemical composition and
  20. the occurrence of mycotoxins. Food Science
  21. and Technology 31(1):172-177.
  22. Fatema, K., F. Rahman, N. Sumi, K. Kobura, and
  23. L. Ali. 2010. Glycemic index of three common
  24. varieties of Bangladeshi rice in healthy subjects.
  25. African Journal of Food Science 4(8):531-535.
  26. Ghadge, P. and K. Prasad. 2012. Some physical
  27. properties of rice kernels: Variety PR-106.
  28. Journal of Food Process Technology 3(8):1-5.
  29. Hasbullah, R. Dan R.D.P. Pramita. 2013. Pengaruh
  30. lama perendaman terhadap mutu beras pratanak
  31. pada varietas IR 64. JTEP Jurnal Keteknikan
  32. Pertanian. 27(1): 53-60. doi: 10.19028/
  33. jtep.27.1.53-60.
  34. Hasbullah, R., L. Pujantoro, S. Koswara, E.
  35. Fadhallah, dan M. Surahman. 2016. Steaming
  36. process of paddy to improve quality and reduce
  37. glycemic index of parboiled rice. III International
  38. Conference on Agricultural and Food Engineering
  39. 1152. hlm 375-380.
  40. Labuza, T.P. 1982. Shelf life dating of foods. Food
  41. and nutrition press. Inc., Westport, Connecticut.
  42. Lievonen, S. And Y. Roos. 2002. Water sorption
  43. of food models for studies of glass transition and
  44. reaction kinetics. Journal of Food Science
  45. 67(5):1758-1766.
  46. Rahayu, W., M. Arpah, dan E. Diah. 2005. Penentuan
  47. waktu kadaluarsa dan model sorpsi isotermis biji
  48. dan bubuk lada hitam (Piper ningrum L.).Jurnal
  49. Teknol. dan Industri Pangan. Vol.XVI, No.1.
  50. Rohman, A., S. Helmiyati, M. Hapsari, dan D.L.
  51. Setyaningrum. 2014. Rice in health and nutrition.
  52. International Food Research Journal 21(1).
  53. Widowati, S., B.A.S. Santosa, M. Astawan, dan
  54. Akhyar. 2009. Penurunan indeks glikemik
  55. berbagai varietas beras melalui proses pratanak.
  56. Jurnal Pascapanen. 6(1):1-9
  57. Widyotomo, S., O.Atmawinata, dan H.K. Purwadaria.
  58. 2011. Karakterisasi isoterm sorpsi air biji kopi
  59. dengan model BET dan GAB. Agritech 31(3).