PERANAN STARTER DAN CRYOPROTECTAN TERHADAP KUALITAS YOGURT BEKU BUAH PEPINO (Enfluence of Starter and Cryoprotectan on Frozen Yogurt of Pepino Fruit) (UPN VETERAN JAWA TIMUR, 2017)
AbstractFrozen yogurt is a type of yogurt as the result of fermentation of milk by lactic acidbacteria (Streptococcus thermophilus and Lactobacillus bulgaricus) which are experiencingthe freezing process. The main problem is a frozen yogurt as the product of freezingprocess which can lead to damage to the cell membrane so that the lactic acid bacteria canreduce 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 cellsurvival of bacteria during freezing. This research aim is to study the effect of starterconcentration and the addition of skim milk as a cryoprotectant compounds on thephysicochemical, microbiological and organoleptic pepino fruit frozen yogurt quality. Theresults showed that the best treatment is on 5 % starter concentration (Streptococcusthermophilus and Lactobacillus bulgaricus) and 10 % skim milk concentration. The treatmentproduces 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), totalcarotenoids 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 concentrationAbstrakYogurt beku merupakan jenis yogurt hasil proses fermentasi susu oleh bakteri asamlaktat (Streptococcu sthermophilus dan Lactobacillus bulgaricus) yang mengalami prosespembekuan. Permasalahan utama produk yoghurt beku adalah proses pembekuan dapatmengakibatkan kerusakan pada membran sel bakteri asam laktat sehingga dapatmenurunkan viabilitas bakteri asam laktat yang berakibat penurunan kualitas yogurt beku.Oleh karena itu perlu ditambahkan senyawa cryoprotectant yang berperanan dalammempertahankan ketahanan sel bakteri selama pembekuan. Penelitian ini bertujuan untukmempelajari pengaruh konsentrasi starter dan penambahan susu skim sebagai senyawacryoprotectant terhadap kualitas fisikokimia, mikrobiologi dan organoleptik) yoghurt bekubuah pepino.Hasil penelitian menunjukkan bahwa perlakuan terbaik terdapat padaperlakuan konsentrasi starter (Streptococcus thermophilus dan Lactobacillus bulgaricus) 5%dan konsentrasi susu skim 10%. Perlakuan tersebut menghasilkan yogurt beku dengankomposisi 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 C15,570 mg/100g dengan tingkat kesukaan rasa sebesar 156, aroma 162,5, warna 133 dantekstur 126.Kata Kunci: yoghurt beku, buah pepino, susu skim, konsentrasi starter