An Evaluation of the Clotting Properties of Three Plant Rennets in the Milks of Different Animal Species.

Katia Liburdi,Gilberto Giangolini,Carlo Boselli,Marco Esti,Simonetta Amatiste

doi:10.3390/foods8120600

Abstract

Cynara cardunculus, Carica papaya and Ficus carica extracts are proposed as milk coagulants herein. Their coagulation efficiency was measured in bovine, buffalo, goat and sheep milk incubated at different temperatures. The milk-clotting and proteolytic activities as well as the lactodynamographic parameters were determined considering animal rennet as a reference coagulant. The vegetable coagulant, extracted from C. cardunculus pistils, proved to be the most suitable milk-clotting enzyme for cheesemaking, since it possesses similar milk clotting properties to conventional calf rennet. F. carica latex, but seemed to be a promising alternative coagulant at higher temperatures. The strong proteolytic activity of papain caused poor milk coagulation in all milk samples. To conclude, this result also supports the original hypothesis of this study that the excessive proteolytic nature of plant coagulants can negatively affect the cheesemaking process. The optimization of using a plant rennet in a dairy application can be done by selecting the appropriate plant rennet with a consistent clotting efficiency. These innovative manufacturing processes may also lead to the optimization and production of new cheese varieties.

Highlights

The first essential biochemical process during cheesemaking is to convert liquid milk into a soft gel called curd
Huppertz et al, [4] reported that alternative coagulants should have similar biochemical properties to those of calf rennet, such as high milk clotting power; high specificity toward κ-casein; proteolytic activity at cheesemaking pH and temperature; and a sufficient thermolability to ensure whey products without residual coagulant activity
Fresh fig latex (Fc) was extracted from the unripe green fruits of F. carica L. tree cultivated in the Botanical Garden of Tuscia University (Viterbo) and collected in a clean tube containing 0.05%

Summary

Introduction

The first essential biochemical process during cheesemaking is to convert liquid milk into a soft gel called curd. Cheese production increased by a factor of 3.5 since 1961 but the rennet supply decreased due to the limited availability of ruminant stomachs [2]. Various factors such as the high price of rennet, religious concerns (e.g., Islam and Judaism), diet (vegetarianism) or a ban on the use of recombinant calf rennet uses (in France, Germany and The Netherlands) have encouraged the search for alternative milk-clotting sources [3]. Huppertz et al, [4] reported that alternative coagulants should have similar biochemical properties to those of calf rennet, such as high milk clotting power; high specificity toward κ-casein; proteolytic activity at cheesemaking pH and temperature; and a sufficient thermolability to ensure whey products without residual coagulant activity. The most commonly used rennet substitutes include enzymes of microbial origin and recombinant proteases metabolised by genetically

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Conclusion