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Microbiological mapping of the production of fruit-based beverages

Martinez Troncoso, Victoria LU (2025) KMBM01 20251
Applied Microbiology
Biotechnology
Biotechnology (MSc)
Abstract
Fruit-based beverages, such as juices and ciders, are widely consumed due to their nutritional
value, but are also susceptible to microbial spoilage, contributing to food waste. This study
aimed to investigate the presence and behaviour of spoilage microorganisms along the
production lines of two fruit-based beverages: apple cider and a pear fruit drink. Sampling was
conducted at various processing stages, and environmental contamination was assessed
through equipment swabs and air testing. Microorganisms were identified using MALDI-TOF
mass spectrometry.
Yeasts, particularly Zygosaccharomyces rouxii, were dominant in raw materials, although high
Brix levels seemed to inhibit their growth. Microbial populations in apple... (More)
Fruit-based beverages, such as juices and ciders, are widely consumed due to their nutritional
value, but are also susceptible to microbial spoilage, contributing to food waste. This study
aimed to investigate the presence and behaviour of spoilage microorganisms along the
production lines of two fruit-based beverages: apple cider and a pear fruit drink. Sampling was
conducted at various processing stages, and environmental contamination was assessed
through equipment swabs and air testing. Microorganisms were identified using MALDI-TOF
mass spectrometry.
Yeasts, particularly Zygosaccharomyces rouxii, were dominant in raw materials, although high
Brix levels seemed to inhibit their growth. Microbial populations in apple concentrate varied
by storage conditions, with Z. rouxii more prevalent in wine-cellar-stored tanks and
Aureobasidium pullulans in outdoor tanks. Filtration proved to be the most effective microbial
control step, while carbonation and preservative addition showed unexpected limited impact.
Equipment swabs revealed widespread microbial presence, highlighting hygiene shortcomings.
The microbial flora of the blending area appeared as more diverse than the wine cellar.
Airborne mould diversity was high, though the organisms were unable to be identified with the
method used. MALDI-TOF MS is a powerful tool for the typing of microorganisms but
changes in the method used are necessary to optimize its possibilities.
This study created a microbial map of contamination sources, offering insights into spoilage
risks and potential improvements for microbial control strategies in beverage production,
ultimately supporting food safety and waste reduction. (Less)
Popular Abstract
Fruit-based beverages, like juices, smoothies, ciders and wines, are a delicious and nutritious part of many diets. Their taste makes them popular with consumers. However, these products can be as well liked within microorganisms, equally aware of their nutritional value.
Fruit-based beverages are generally protected against harmful pathogens thanks to their acidity. However, certain bacteria, yeast and moulds can still grow, known as spoilage microorganisms. These affect the quality of the beverages, turning drinks sour or even producing visible mould. Food spoilage is responsible for a big percentage of food waste worldwide.
But which microbial intruders are present and how do they end up in the final product? That’s the main... (More)
Fruit-based beverages, like juices, smoothies, ciders and wines, are a delicious and nutritious part of many diets. Their taste makes them popular with consumers. However, these products can be as well liked within microorganisms, equally aware of their nutritional value.
Fruit-based beverages are generally protected against harmful pathogens thanks to their acidity. However, certain bacteria, yeast and moulds can still grow, known as spoilage microorganisms. These affect the quality of the beverages, turning drinks sour or even producing visible mould. Food spoilage is responsible for a big percentage of food waste worldwide.
But which microbial intruders are present and how do they end up in the final product? That’s the main question addressed in this project. In most cases, they are part of an environmental or raw material contamination. Fruits and vegetables naturally carry microorganisms in their surface, but these are removed during processing. Still, contamination can occur through equipment, insufficient hygiene or even via the air in the production facility.
During this project, the production line of two different fruit-based beverages was followed, collecting samples at different stages. This helped assess the effectivity of processing steps, like preservative addition or filtration, observing their impact in the microorganisms in the products. Environmental contamination was also studied, by measuring microbial presence in equipment and air. Once detected, the identification was done with MALDI-TOF mass spectrometry, a technique that can pinpoint the specific organisms present.
This study created a “microbial map”, showing where and when microorganisms appeared and disappeared throughout the production process. By analysing how parameters and processes affected the microbial flora, this projects helps locate potential issues and optimize the production, ensuring safety and reducing food waste. (Less)
Please use this url to cite or link to this publication:
author
Martinez Troncoso, Victoria LU
supervisor
organization
alternative title
Mikrobiologisk kartläggning av produktionen av fruktbaserade drycker.
course
KMBM01 20251
year
type
H2 - Master's Degree (Two Years)
subject
keywords
applied microbiology, microbiology, juice industry, yeast, mould, bacteria, MALDI-TOF, product quality, product safety
language
English
id
9203140
date added to LUP
2025-06-23 09:10:03
date last changed
2025-06-25 08:53:39
@misc{9203140,
  abstract     = {{Fruit-based beverages, such as juices and ciders, are widely consumed due to their nutritional 
value, but are also susceptible to microbial spoilage, contributing to food waste. This study 
aimed to investigate the presence and behaviour of spoilage microorganisms along the 
production lines of two fruit-based beverages: apple cider and a pear fruit drink. Sampling was 
conducted at various processing stages, and environmental contamination was assessed 
through equipment swabs and air testing. Microorganisms were identified using MALDI-TOF 
mass spectrometry. 
Yeasts, particularly Zygosaccharomyces rouxii, were dominant in raw materials, although high 
Brix levels seemed to inhibit their growth. Microbial populations in apple concentrate varied 
by storage conditions, with Z. rouxii more prevalent in wine-cellar-stored tanks and 
Aureobasidium pullulans in outdoor tanks. Filtration proved to be the most effective microbial 
control step, while carbonation and preservative addition showed unexpected limited impact. 
Equipment swabs revealed widespread microbial presence, highlighting hygiene shortcomings. 
The microbial flora of the blending area appeared as more diverse than the wine cellar. 
Airborne mould diversity was high, though the organisms were unable to be identified with the 
method used. MALDI-TOF MS is a powerful tool for the typing of microorganisms but 
changes in the method used are necessary to optimize its possibilities. 
This study created a microbial map of contamination sources, offering insights into spoilage 
risks and potential improvements for microbial control strategies in beverage production, 
ultimately supporting food safety and waste reduction.}},
  author       = {{Martinez Troncoso, Victoria}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Microbiological mapping of the production of fruit-based beverages}},
  year         = {{2025}},
}