Effect of biological treatment used before harvesting and storage methods on the quality, health and microbial characteristics of unripe hazelnut in the husk (Corylus avellana L.)

Bogumił Markuszewski; Anna Adriana Bieniek; Urszula Wachowska; Arkadiusz Bieniek; Izabela Krzymińska

doi:10.7717/peerj.12760

Effect of biological treatment used before harvesting and storage methods on the quality, health and microbial characteristics of unripe hazelnut in the husk (Corylus avellana L.)

PeerJ. 2022 Jan 28:10:e12760. doi: 10.7717/peerj.12760. eCollection 2022.

Authors

Bogumił Markuszewski¹, Anna Adriana Bieniek¹, Urszula Wachowska², Arkadiusz Bieniek³, Izabela Krzymińska⁴

Affiliations

¹ Department of Agroecosystems and Horticulture, University of Warmia and Mazury in Olsztyn, Olsztyn, Warmia and Mazury, Poland.
² Department of Entomology, Phytopathology and Molecular Diagnostics, University of Warmia and Mazury in Olsztyn, Olsztyn, Warmia and Mazury, Poland.
³ Department of Soil Science and Microbiology, University of Warmia and Mazury in Olsztyn, Olsztyn, Warmia and Mazury, Poland.
⁴ Institute of Microbiological Technologies in Turek, Turek, Poland.

Abstract

Background: The hazelnut (Corylus avellana) is still one of the most profitable nut crop species. In recent years, however, there has been growing interest in this species in the form of "fresh nuts" that are picked before falling out of the fruit cover. The aim of this study was to evaluate the effect of storage conditions for hazelnuts protected with biological preparations on selected morphological features of the fruits, their health status and the count of bacteria and fungi colonizing the fruits.

Results: The hazelnuts harvested from the trees protected with a preparation containing Pythium oligandrum and stored for 2 months under the controlled atmosphere conditions and in Xtend® bags (MAP) had the greatest weight and the highest percentage of the kernel. After 3 months of storage, the hazelnuts had reduced commercial value. Only a few hazelnuts displayed symptoms of infectious diseases caused by species of Botrytis and Monilia. The protection applied before the hazelnut harvesting contributed to a multiple increase in the bacterial and yeasts count on the husks and shells of the hazelnuts stored for 3 months. The bacterial count on the nuts stored under the controlled atmosphere (CA, 3%O₂:3%CO₂, a temperature of 0-1 °C, humidity of 85-95%) and under the controlled atmosphere conditions and in Xtend® bags (MAP) increased significantly. An analysis of the ITS region sequence revealed the presence of bacteria Arthrobacter luteolus and Pantoea agglomerans. A Koch test proved that both non-pathogenic bacteria and pathogenic fungi can cause the browning of the C. avellana leaf under conditions of high humidity. The application of a controlled atmosphere is recommended for a short-term storage of hazelnuts in the husk.

Conclusion: This research showed that 2 months' storage of hazelnuts under controlled atmosphere conditions and Xtend® bags (MAP) prevented a reduction in the weight of hazelnuts in the husk, without the husk, and of the kernel and prevented the nut separation from the husk. In general, the application of biopreparations for the protection of the hazelnut had a positive effect on the kernel weight and size.

Keywords: Arthrobacter; Cladosporium; Fresh hazelnut; Pantoea; Probiotics; Pythium oligandrum.

Publication types

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

MeSH terms

Corylus*
Nuts
Skin
Temperature

Grants and funding

The results presented in this paper were obtained as part of a comprehensive study financed by the University of Warmia and Mazury in Olsztyn, Faculty of Agriculture and Forestry, Department of Agroecosystems and Horticulture, 30.610.016-110. This project was financially supported by the Minister of Education and Science in the range of the program entitled “Regional Initiative of Excellence” for the years 2019–2022, Project No. 010/RID/2018/19, amount of funding PLN 12 000 000. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.