Noni (Morinda citrifolia L.) fruit as a new source of milk-clotting cysteine proteases

Vilmara Albuquerque de Farias; Amanda Dias da Rocha Lima; Andréa Santos Costa; Cléverson Diniz T de Freitas; Idila Maria da Silva Araújo; Deborah Dos Santos Garruti; Evânia Altina Teixeira de Figueiredo; Hermógenes David de Oliveira

doi:10.1016/j.foodres.2019.108689

Noni (Morinda citrifolia L.) fruit as a new source of milk-clotting cysteine proteases

Food Res Int. 2020 Jan:127:108689. doi: 10.1016/j.foodres.2019.108689. Epub 2019 Oct 8.

Authors

Vilmara Albuquerque de Farias¹, Amanda Dias da Rocha Lima¹, Andréa Santos Costa¹, Cléverson Diniz T de Freitas¹, Idila Maria da Silva Araújo², Deborah Dos Santos Garruti², Evânia Altina Teixeira de Figueiredo³, Hermógenes David de Oliveira⁴

Affiliations

¹ Department of Biochemistry and Molecular Biology, Federal University of Ceará, Campus do Pici Prof. Prisco Bezerra, 60.440-900 Fortaleza, CE, Brazil.
² Embrapa Agroindústria Tropical, Rua Dra. Sara Mesquita, no 2270, 60.511-110 Fortaleza, CE, Brazil.
³ Department of Food Technology, Federal University of Ceará, Campus do Pici Prof. Prisco Bezerra, 60.356-000 Fortaleza, CE, Brazil.
⁴ Department of Biochemistry and Molecular Biology, Federal University of Ceará, Campus do Pici Prof. Prisco Bezerra, 60.440-900 Fortaleza, CE, Brazil. Electronic address: hermogenes@ufc.br.

PMID: 31882081
DOI: 10.1016/j.foodres.2019.108689

Abstract

This work reports the characterisation of caseinolytic and milk-clotting activities of proteases extracted from ripe fruits of Morinda citrifolia L., as a potential of their use in cheese production. Noni puree extract (NPE) was obtained by homogenising the fresh puree in 150 mM NaCl/50 mM sodium phosphate buffer (pH 7.0). The resulting protein concentration was of 0.367 ± 0.006 mg/mL, and an electrophoretic profile of the extract revealed protein bands ranging from 14 to 55 kDa. The proteolytic activity of NPE was higher when the extract had been previously incubated at pH 6.0 (8.859 ± 0.216 U/mg), whereas the optimum caseinolytic activity was observed at 50 °C. Noni puree proteases were strongly (98%) inhibited by iodoacetamide and E-64, suggesting the presence of only cysteine proteases in the crude extract. NPE proteases showed a milk-clotting activity (MCA) of 238.80 ± 5.29 U/mL, a specific milk-clotting activity (SMCA) of 9950.17 ± 220.74 U/mg, and an SMCA/PA ratio of 1124.31 ± 24.94, this last being comparable to those of commercial calf rennet. The cheese manufactured using NPE presented brittle and soft texture, high humidity, and showed sanitary conditions compatible with current Brazilian regulations. The product showed a slightly bitter taste, but still good acceptability, rating between 6 and 7 in the hedonic scale for flavour, texture, and overall acceptance. Lastly, there was 60% of positive purchase intent, demonstrating that noni fruit is a promising source of milk-clotting enzymes for the dairy industry.

Keywords: Azocasein (PubChem CID: 39859) β-mercaptoethanol (PubChem CID: 1567); Casein (PubChem CID: 73995022); Cysteine proteases; Dairy industry; Dithiothreitol (PubChem CID: 19001); Ethylenediaminetetraacetic acid (Pub Chem CID: 6049); Iodoacetamide (PubChem CID: 3727); Morinda citrifolia L.; Pepstatin A (PubChem CID: 4742); Phenylmethylsulfonyl fluoride (PubChem CID: 4784); Plant coagulant; Trans-epoxy-succinyl-1-leucyl-amido (4-guanidino) butane (E-64) (PubChem CID: 439487); Triton X-100 (PubChem CID: 5590).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Brazil
Cheese*
Cysteine Proteases / metabolism*
Food Handling / methods
Fruit / metabolism*
Milk / metabolism*
Morinda / metabolism*
Plant Extracts / metabolism*

Substances

Plant Extracts
Cysteine Proteases