Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese

The food industry generates large quantities of biowaste, including olive (<i>Olea europaea</i> L.) leaves, which are rich in phenolic compounds with proven antioxidant and antimicrobial activity. In this study, a microwave-assisted olive leaf extract was produced and evaluated. Antioxid...

Full description

Saved in:
Bibliographic Details
Main Authors: Elizabeta Zandona, Maja Vukelić, Karla Hanousek Čiča, Antonio Zandona, Jasna Mrvčić, Maja Katalinić, Ines Cindrić, Almir Abdurramani, Irena Barukčić Jurina
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Foods
Subjects:
Online Access:https://www.mdpi.com/2304-8158/14/9/1496
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850155880851439616
author Elizabeta Zandona
Maja Vukelić
Karla Hanousek Čiča
Antonio Zandona
Jasna Mrvčić
Maja Katalinić
Ines Cindrić
Almir Abdurramani
Irena Barukčić Jurina
author_facet Elizabeta Zandona
Maja Vukelić
Karla Hanousek Čiča
Antonio Zandona
Jasna Mrvčić
Maja Katalinić
Ines Cindrić
Almir Abdurramani
Irena Barukčić Jurina
author_sort Elizabeta Zandona
collection DOAJ
description The food industry generates large quantities of biowaste, including olive (<i>Olea europaea</i> L.) leaves, which are rich in phenolic compounds with proven antioxidant and antimicrobial activity. In this study, a microwave-assisted olive leaf extract was produced and evaluated. Antioxidant potential (20.23 ± 0.31 µmol TE g<sup>−1</sup>), antimicrobial activity against <i>Staphylococcus aureus</i> (MIC 17.62 mg GAE g<sup>−1</sup>), and cytotoxic effects in breast (MDA-MB-231 (IC<sub>50</sub> = 38.9 ± 1.8 µg mL<sup>−1</sup>), MCF-7 (IC<sub>50</sub> = 58.9 ± 5.4 µg mL<sup>−1</sup>) and prostate cancer PC-3 (IC<sub>50</sub> = 69.2 ± 7.6 µg mL<sup>−1</sup>) cell models were confirmed. Further, the extract was incorporated into a whey protein isolate (WPI) edible coating mixture and applied to semi-hard cheese over a 60-day ripening period. When applied to cheese, WPI-based coatings enriched with OLE contributed to an improved antioxidant potential (289.79 ± 16.16 µmol TE L<sup>−1</sup>), elevated retention of total phenols and flavonoids, and slightly reduced microbial growth without compromising cheese safety. Compared to the uncoated control, coated samples showed higher total solids (up to 62.87 ± 0.13%, CWPIM) and fat contents (up to 26.59 ± 0.17%, CWPIM), moderated proteolysis (WSN in CWPIM: 3.15 ± 0.09% vs. 4.48 ± 0.02% in C0), maintained cohesiveness and resilience compared to the control, and exhibited less pronounced color deviation (ΔE) in some coated samples during ripening. These results highlight the potential of olive leaf extract as a bioactive, sustainable ingredient for functional edible coatings that improve the nutritional, technological, and microbiological quality of ripened cheese.
format Article
id doaj-art-2ef9168fa2f4474184fa12e1a8f983cb
institution OA Journals
issn 2304-8158
language English
publishDate 2025-04-01
publisher MDPI AG
record_format Article
series Foods
spelling doaj-art-2ef9168fa2f4474184fa12e1a8f983cb2025-08-20T02:24:46ZengMDPI AGFoods2304-81582025-04-01149149610.3390/foods14091496Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard CheeseElizabeta Zandona0Maja Vukelić1Karla Hanousek Čiča2Antonio Zandona3Jasna Mrvčić4Maja Katalinić5Ines Cindrić6Almir Abdurramani7Irena Barukčić Jurina8Department of Food Technology, Karlovac University of Applied Sciences, Trg J.J. Strossmayera 9, 47000 Karlovac, CroatiaDepartment of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaDepartment of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaDivision of Toxicology, Institute for Medical Research and Occupational Health, Ksaverska Cesta 2, 10000 Zagreb, CroatiaDepartment of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaDivision of Toxicology, Institute for Medical Research and Occupational Health, Ksaverska Cesta 2, 10000 Zagreb, CroatiaDepartment of Food Technology, Karlovac University of Applied Sciences, Trg J.J. Strossmayera 9, 47000 Karlovac, CroatiaFaculty of Food Technology, Josip Juraj Strossmayer University of Osijek, Franje Kuhača 18, 31000 Osijek, CroatiaDepartment of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaThe food industry generates large quantities of biowaste, including olive (<i>Olea europaea</i> L.) leaves, which are rich in phenolic compounds with proven antioxidant and antimicrobial activity. In this study, a microwave-assisted olive leaf extract was produced and evaluated. Antioxidant potential (20.23 ± 0.31 µmol TE g<sup>−1</sup>), antimicrobial activity against <i>Staphylococcus aureus</i> (MIC 17.62 mg GAE g<sup>−1</sup>), and cytotoxic effects in breast (MDA-MB-231 (IC<sub>50</sub> = 38.9 ± 1.8 µg mL<sup>−1</sup>), MCF-7 (IC<sub>50</sub> = 58.9 ± 5.4 µg mL<sup>−1</sup>) and prostate cancer PC-3 (IC<sub>50</sub> = 69.2 ± 7.6 µg mL<sup>−1</sup>) cell models were confirmed. Further, the extract was incorporated into a whey protein isolate (WPI) edible coating mixture and applied to semi-hard cheese over a 60-day ripening period. When applied to cheese, WPI-based coatings enriched with OLE contributed to an improved antioxidant potential (289.79 ± 16.16 µmol TE L<sup>−1</sup>), elevated retention of total phenols and flavonoids, and slightly reduced microbial growth without compromising cheese safety. Compared to the uncoated control, coated samples showed higher total solids (up to 62.87 ± 0.13%, CWPIM) and fat contents (up to 26.59 ± 0.17%, CWPIM), moderated proteolysis (WSN in CWPIM: 3.15 ± 0.09% vs. 4.48 ± 0.02% in C0), maintained cohesiveness and resilience compared to the control, and exhibited less pronounced color deviation (ΔE) in some coated samples during ripening. These results highlight the potential of olive leaf extract as a bioactive, sustainable ingredient for functional edible coatings that improve the nutritional, technological, and microbiological quality of ripened cheese.https://www.mdpi.com/2304-8158/14/9/1496biowasteolive leavesbioactivitiesedible coatingdairyripening
spellingShingle Elizabeta Zandona
Maja Vukelić
Karla Hanousek Čiča
Antonio Zandona
Jasna Mrvčić
Maja Katalinić
Ines Cindrić
Almir Abdurramani
Irena Barukčić Jurina
Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
Foods
biowaste
olive leaves
bioactivities
edible coating
dairy
ripening
title Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
title_full Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
title_fullStr Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
title_full_unstemmed Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
title_short Bioactive Properties of the Microwave-Assisted Olive Leaf Extract and Its Incorporation into a Whey Protein Isolate Coating of Semi-Hard Cheese
title_sort bioactive properties of the microwave assisted olive leaf extract and its incorporation into a whey protein isolate coating of semi hard cheese
topic biowaste
olive leaves
bioactivities
edible coating
dairy
ripening
url https://www.mdpi.com/2304-8158/14/9/1496
work_keys_str_mv AT elizabetazandona bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT majavukelic bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT karlahanousekcica bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT antoniozandona bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT jasnamrvcic bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT majakatalinic bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT inescindric bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT almirabdurramani bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese
AT irenabarukcicjurina bioactivepropertiesofthemicrowaveassistedoliveleafextractanditsincorporationintoawheyproteinisolatecoatingofsemihardcheese