Characterization of the microbiological population and presence on Swedish greenhouse grown cucumbers during shelf life at different storage and treatment conditions
(2023) KLGM01 20231Food Technology and Nutrition (M.Sc.)
- Abstract
- Nearly one third of the global food is wasted. Microbial spoilage is a major factor in food waste, and it can happen at any point along the supply chain. Greenhouse grown English long cucumbers, one of the most important vegetable crops grown in Europe, were studied for weight changes and the presence of microbiological populations during the shelf life in this project. The main methods used in this thesis were plate counting and Sanger sequencing. Six naked cucumber batches were tested in the study for a total of 12 days shelf-life and were assessed at 6-day intervals. The first four batches evaluated the changes in the microorganism loads of cucumber at 4 °C and 12 °C storage, including total plate count, mould and yeast, and... (More)
- Nearly one third of the global food is wasted. Microbial spoilage is a major factor in food waste, and it can happen at any point along the supply chain. Greenhouse grown English long cucumbers, one of the most important vegetable crops grown in Europe, were studied for weight changes and the presence of microbiological populations during the shelf life in this project. The main methods used in this thesis were plate counting and Sanger sequencing. Six naked cucumber batches were tested in the study for a total of 12 days shelf-life and were assessed at 6-day intervals. The first four batches evaluated the changes in the microorganism loads of cucumber at 4 °C and 12 °C storage, including total plate count, mould and yeast, and Enterobacteriaceae. The batches 5 and 6 investigated the impact of water rinsing before the storage on the corresponding microorganism loads of cucumbers stored at 12 °C and the potential identification of species.
The findings showed significant heterogeneity across batches and between individual cucumbers. The weight of naked cucumbers declined with storage time, especially cucumbers stored at 12 °C lost more weight than cucumbers stored at 4 °C. The total plate count could best reflect the overall microbial carrying capacity of cucumbers. Cucumbers stored at different temperatures did not show significant differences in the microbiological analysis. Furthermore, though rinsing under running cold tap water may lower the quantity of microorganisms on fresh cucumber, a more extended storage period may result in accelerated microbial growth. Curtobacterium, Mammaliicoccus, Microbacterium, Pseudomonas, Stenotrophomonas, and Staphylococcus were found in both washed and unwashed groups from Trypticase Soy Agar plates. Apart from that, Aerococcus, Agrobacterium, Buttiauxella, Enterobacter and Klebsiella, among others were also detected in the unwashed group. Given the heterogeneity of cucumber quality and the small experimental sample size, it can be recommended to increase the sample sizes in the future while limiting the source of cucumbers. Based on this concept, more experimental comparisons with typical plastic-wrapped cucumbers could be carried out to achieve more information about cucumber shelf-life research. (Less) - Popular Abstract
- How much do you know about cucumbers? How do you typically consume cucumbers? It can be pickled, sliced into salads, or cooked. Then you may probably wonder how to treat your cucumbers, how to store cucumbers and how long they can be stored.
The cucumber (Cucumis sativus L.) belongs to the Cucurbitaceae family. They are thought to have originated in Africa, China, India, or the Near East. The Romans brought it to Greece and Italy later, and it was cultivated almost throughout Europe during the Middle Ages. There are lots of cultivar groups globally. For example, French cornichons look small and spiny and are suitable for pickling; Far Eastern cucumbers are long and have visible warts and spines on the surface, which are suitable for... (More) - How much do you know about cucumbers? How do you typically consume cucumbers? It can be pickled, sliced into salads, or cooked. Then you may probably wonder how to treat your cucumbers, how to store cucumbers and how long they can be stored.
The cucumber (Cucumis sativus L.) belongs to the Cucurbitaceae family. They are thought to have originated in Africa, China, India, or the Near East. The Romans brought it to Greece and Italy later, and it was cultivated almost throughout Europe during the Middle Ages. There are lots of cultivar groups globally. For example, French cornichons look small and spiny and are suitable for pickling; Far Eastern cucumbers are long and have visible warts and spines on the surface, which are suitable for cooking and slicing. In this project, European greenhouse cucumbers are the main subject, or you can call them greenhouse grown English long cucumbers. These cucumbers are self-pollinating, which means they do not require the assistance of bees, other animals, or the wind to produce fruit. They are long, straight and smooth, with a dark green outer skin and a light green interior with small seeds. Usually, when you see them in supermarkets such as ICA, they are in plastic wrapping.
Nowadays, food waste and loss are global issues. Food waste caused by the proliferation of microorganisms is an important factor. This thesis will discuss the fluctuation of microorganism counts on cucumbers at 4 °C and 12 °C during the shelf life and cucumber weight loss. Also, we will discuss the impact of water rinsing at the beginning of the shelf life on the corresponding microorganism loads on cucumbers stored at 12 °C and the potential identification of bacterial species.
Storage at different temperatures did not lead to significant differences in the microbial counts of cucumbers during the shelf life. It could be stated that the weight loss of naked cucumbers stored at 12 °C exceeded 20 %, while the weight loss of those stored at 4 °C ranged from 10 % to 20 % after two weeks. Furthermore, rinsing fresh cucumbers before eating could help to remove some bacteria but could not avoid the bacterial safety issue completely. In the future, we hope to carry out more parallel experiments or compare them with wrapped cucumbers to understand better how to extend the shelf-life of cucumbers and ensure food safety. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9138836
- author
- Chu, Rui LU
- supervisor
- organization
- course
- KLGM01 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- English long cucumber, greenhouse-grown, weight loss, shelf life, microbiology, food technology
- language
- English
- id
- 9138836
- date added to LUP
- 2023-09-26 09:58:43
- date last changed
- 2023-09-26 09:58:43
@misc{9138836,
abstract = {{Nearly one third of the global food is wasted. Microbial spoilage is a major factor in food waste, and it can happen at any point along the supply chain. Greenhouse grown English long cucumbers, one of the most important vegetable crops grown in Europe, were studied for weight changes and the presence of microbiological populations during the shelf life in this project. The main methods used in this thesis were plate counting and Sanger sequencing. Six naked cucumber batches were tested in the study for a total of 12 days shelf-life and were assessed at 6-day intervals. The first four batches evaluated the changes in the microorganism loads of cucumber at 4 °C and 12 °C storage, including total plate count, mould and yeast, and Enterobacteriaceae. The batches 5 and 6 investigated the impact of water rinsing before the storage on the corresponding microorganism loads of cucumbers stored at 12 °C and the potential identification of species.
The findings showed significant heterogeneity across batches and between individual cucumbers. The weight of naked cucumbers declined with storage time, especially cucumbers stored at 12 °C lost more weight than cucumbers stored at 4 °C. The total plate count could best reflect the overall microbial carrying capacity of cucumbers. Cucumbers stored at different temperatures did not show significant differences in the microbiological analysis. Furthermore, though rinsing under running cold tap water may lower the quantity of microorganisms on fresh cucumber, a more extended storage period may result in accelerated microbial growth. Curtobacterium, Mammaliicoccus, Microbacterium, Pseudomonas, Stenotrophomonas, and Staphylococcus were found in both washed and unwashed groups from Trypticase Soy Agar plates. Apart from that, Aerococcus, Agrobacterium, Buttiauxella, Enterobacter and Klebsiella, among others were also detected in the unwashed group. Given the heterogeneity of cucumber quality and the small experimental sample size, it can be recommended to increase the sample sizes in the future while limiting the source of cucumbers. Based on this concept, more experimental comparisons with typical plastic-wrapped cucumbers could be carried out to achieve more information about cucumber shelf-life research.}},
author = {{Chu, Rui}},
language = {{eng}},
note = {{Student Paper}},
title = {{Characterization of the microbiological population and presence on Swedish greenhouse grown cucumbers during shelf life at different storage and treatment conditions}},
year = {{2023}},
}