On Monday, April 11, 2022, the Food Industry Sanitation course of TPHP UGM held a guest lecture with the topic “Application of Sanitation in the Dairy Industry”. This guest lecture was presented by Aditya Putra Nugraha, S.T.P., who is the Plant Quality Manager of Jogja Factory PT Sarihusada General Mahardika. The guest lecture which took place at 11:00 – 13:00 WIB was hosted by Rachma Wikandari, S.T.P., M.Biotech, Ph.D.
Cleaning is the process of cleaning or freeing a surface from all dirt or other substances without affecting or damaging the surface to be cleaned. The purpose of the cleaning process is to clean the surface of the tool or machine from dirt and contamination because this will directly affect food quality.
The parts that need to be cleaned are product contact surfaces, surfaces that come into contact with hands or feet, and places where bacteria can grow and hide. Product contact surfaces, such as pipes through which milk flows, processing machines, knives, and ingredient tables. Surfaces that come into contact with hands or feet, such as door handles, manholes, glassware, refrigeration machines, floors, walls, glass, and other surfaces. Places where bacteria live and grow, such as workers’ clothing, cleaning supplies (brooms, brushes, rags, mops, etc.), awful bins (reject products), trash cans, and water traps.
Materials used for cleaning are detergents, disinfectants (hot water, steam, chemicals), and sanitizers. Detergents are used to remove dirt, dust, and grease. Disinfectants help reduce the growth of bacteria to safe levels. Disinfectants and sanitizers are chemicals that work to reduce the number of growing microorganisms and their spores to safe levels for humans.
The various impurities in the dairy industry are sugar, fat, protein, and mineral salts. Sugar is soluble in water and easy to clean, but if exposed to heating it caramelizes and is difficult to clean. Fat is soluble in alkali but insoluble in water and difficult to clean, if exposed to the heating process it will undergo polymerization, making it even more difficult to clean. Proteins are soluble in alkali, slightly soluble in acid but insoluble in water, and very difficult to clean, if exposed to heating, they will denature, making them more difficult to clean. Mineral salts are water-soluble, some are acid-soluble, the degree of cleaning is from easy to difficult, and the heating process does not affect the surface cleaning process much.
The steps of cleaning and disinfection in the CIP (Cleaning In Place) process are initial washing, alkaline recirculation, water rinsing, acid recirculation, and final rinsing. The initial rinse removes dirt so that the cleaning power of the detergent is not weakened and minimizes the amount of chemicals to be used. The alkaline recirculation serves to remove proteins and fats. The second wash is used to remove residual alkali. Acid recirculation is used to remove dirt deposits. The final rinse is used to remove residual acid.
The alkali used as a cleaning agent is NaOH (Sodium Hydroxide) which has a bactericidal function and removes protein, fat, and sugar. NaOH is used at a concentration of 1 – 1.5%, pH 13 – 13.5, and a minimum temperature of 80°C. Meanwhile, the acids used as cleaning agents are HNO3 (Nitric Acid) and H3PO4 (Phosphoric Acid) which have the effect of killing spores and removing mineral deposits, fats, sugars, and proteins. HNO3 and H3PO4 are used at a concentration of 0.6 to 1.2%, a pH of 1.5, and an ambient temperature of 60 to 80°C.
