Pembuatan dan Karakterisasi Sabun Susu dengan Proses Dingin - Diah S. Retnowati; Andri C. Kumoro; Ratnawati; Catarina S. Budiyati (Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada, 2013)
Pada penelitian ini, sabun susu dibuat dari larutan susu-NaOH dengan campuran minyak yang terdiri dari minyak sawit, minyak kelapa, minyak jarak dan minyak canola. Tujuan penelitian adalah mempelajari pengaruh perbandingan massa minyak kelapa terhadap minyak canola dan konsentrasi asam sitrat terhadap pH sabun, kekerasan sabun, kemampuan pembentukan busa dan derajat kebersihan. Percobaan dilakukan dengan menuangkan larutan susu-NaOH dan asam sitrat ke dalam campuran minyak dengan perbandingan berat tertentu dan diaduk dengan kecepatan 400 rpm. Setelah terjadi trace (jejak putaran pada larutan) larutan tersebut dicetak dan didiamkan selama 24 jam. Produk sabun dianalisis kekerasan, pH, kemampuan pembentukan busa dan derajat pembersihan setelah dilakukan proses pemeraman selama 4 minggu. Hasil penelitian menunjukkan bahwa 2% massa asam sitrat dapat menurunkan pH sabun dari 10,2 menjadi 9,8, tetapi juga menurunkan tingkat kekerasan, kemampuan pembentukan busa dan kemampuan membersihkan. Perubahan rasio massa minyak kelapa terhadap minyak canola dari 0,5-2, hanya berpengaruh terhadap kekerasan sabun. Kata Kunci: sabun susu, proses dingin, pH, kekerasan, tingkat kebersihan, pembentukan busa In this research, cold process was chosen to make soap from lye (NaOH solution) and mixture of palm, coconut, castor, and canola oils with certain ratio. This conducted research is to study the effect of palm to canola oil mass ratio and citric acid concentration on pH, hardness, foaming capacity and the cleansing power of the soap. The soap formation was first conducted by dissolving NaOH in the milk with certain concentration sufficient for the oil mixture saponification. The solution and citric acid solution were then added to the oil mixture and was stirred at 400 rpm. After trace occurred, the mixture was transferred to a mold and then was put in an open space for 24 hours. The soap was taken out from the mold and was cured for 4 weeks. The hardness, pH, the foaming capacity, and the cleansing power of the resulted soap were analyzed. The result show that the addition of 2% of citric acid reduces the pH of the soap from 10.2 to 9.8, the hardness, the foaming capacity, and the cleansing ability of the soap. The variation of the ratio of the mass of coconut to canola oil from 0.5 to 2 affects only the hardness of the soap. Keywords: milk-soap, cold process, pH, hardness, cleansing power, lathering