Use of <i>Pergularia tomentosa</i> Plant Enzymatic Coagulant System in Fresh Cheese-Making

Abstract

Introduction : Pergularia tomentosa is a saharan spontaneous plant belonging to Asclepiadacea family. It has several medicinal properties and uses in the human food as an auxiliary in cheese-making. The purpose of this study is the extraction of the coagulant enzymatic system (C.E.S) from the plant dried leaves and its use in the preparation of fresh cheese. Materials & Methods : The determination of the coagulant activity was carried out on a skimmed milk powder by Berridge’s method. Cow’s milk used for coagulant strength deter mination and cheese-making. Proteolytic activity . The chemical determinations of raw milk were carried out according to AFNOR analysis methods. A descriptive sensory evaluation was performed to determine the organoleptic pro perties of the produced cheese. The proteolytic activity was determined b y measuring the aspartyl-protease units. Results: The main results of the phy sico-chemical characterization show that its coagulant activity (R.U mL -1 ) was 97.19 ± 4.67, coagulant strength (SU) was 230.05 ± 0.37, proteolytic activity (μg · mL -1 ) was 0.33 ± 0.04 and coagulant activity/proteolytic activity ratio was 294.51. For the cheese made, it has presented the following results as % (g/100g): titrable acidity 0.80 ± 0.005, total dry extract 30.48 ± 1.490, fat 2 . 32 ± 0.02, fresh yield 11.5 ± 0 . 09, dry yield 30.06 ± 0.05. Moreover, sensory analysis results showed that fresh cheese prepared from Pergularia tomentosa dried leaves diluted enzymatic extract filtrate was characterized by whitish color , smooth texture, with acceptable and satisfying lactic taste. Conclusion: The plant enzymatic system studied could be added to the list of plant rennet substitutes and, thus, contribute s to the manufacture of enzymatic coagula tion cheese.