PERANAN STARTER DAN CRYOPROTECTAN TERHADAP KUALITAS YOGURT BEKU BUAH PEPINO (Enfluence of Starter and Cryoprotectan on Frozen Yogurt of Pepino Fruit)

Abstract

Abstract
Frozen yogurt is a type of yogurt as the result of fermentation of milk by lactic acid
bacteria (Streptococcus thermophilus and Lactobacillus bulgaricus) which are experiencing
the freezing process. The main problem is a frozen yogurt as the product of freezing
process which can lead to damage to the cell membrane so that the lactic acid bacteria can
reduce the viability of lactic acid bacteria which result in loss of quality frozen yogurt.
Therefore, it should be added cryoprotectant compounds that play a role in maintaining cell
survival of bacteria during freezing. This research aim is to study the effect of starter
concentration and the addition of skim milk as a cryoprotectant compounds on the
physicochemical, microbiological and organoleptic pepino fruit frozen yogurt quality. The
results showed that the best treatment is on 5 % starter concentration (Streptococcus
thermophilus and Lactobacillus bulgaricus) and 10 % skim milk concentration. The treatment
produces frozen yogurt with a total composition of lactic acid bacteria 8.735 log CFU / ml,
the viability of lactic acid bacteria 98.471%, melt velocity 19.444 (menit/5gr), total
carotenoids mg/100g 68.278, Vitamin C15.570 mg/100g with the level of preference sense
(156), aroma (162.5), color (133) and texture (126).
Keywords: frozen yogurt, pepino fruit, skim milk, starter concentration

Abstrak
Yogurt beku merupakan jenis yogurt hasil proses fermentasi susu oleh bakteri asam
laktat (Streptococcu sthermophilus dan Lactobacillus bulgaricus) yang mengalami proses
pembekuan. Permasalahan utama produk yoghurt beku adalah proses pembekuan dapat
mengakibatkan kerusakan pada membran sel bakteri asam laktat sehingga dapat
menurunkan viabilitas bakteri asam laktat yang berakibat penurunan kualitas yogurt beku.
Oleh karena itu perlu ditambahkan senyawa cryoprotectant yang berperanan dalam
mempertahankan ketahanan sel bakteri selama pembekuan. Penelitian ini bertujuan untuk
mempelajari pengaruh konsentrasi starter dan penambahan susu skim sebagai senyawa
cryoprotectant terhadap kualitas fisikokimia, mikrobiologi dan organoleptik) yoghurt beku
buah pepino.Hasil penelitian menunjukkan bahwa perlakuan terbaik terdapat pada
perlakuan konsentrasi starter (Streptococcus thermophilus dan Lactobacillus bulgaricus) 5%
dan konsentrasi susu skim 10%. Perlakuan tersebut menghasilkan yogurt beku dengan
komposisi total bakteri asam laktat 8,735 log CFU/ml, viabilitas bakteri asam laktat 98,471%,
kecepatan meleleh 19,444 (menit/5gr), total karoten 68,278 mg/100g, kadar Vitamin C
15,570 mg/100g dengan tingkat kesukaan rasa sebesar 156, aroma 162,5, warna 133 dan
tekstur 126.
Kata Kunci: yoghurt beku, buah pepino, susu skim, konsentrasi starter