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Developing microscopy methods for evaluating bio-processed Brewers Spent Grain (BSG)

Jacob, Sera Susan LU (2019) In Master Thesis KLGM01 20191
Food Technology and Nutrition (M.Sc.)
Abstract
Spent grain (BSG) is the solid residue obtained during brewing containing leftover
malt and adjuncts. Though nutrient-dense, it is found to negatively impact texture and colour when used its raw form as an ingredient in food. Bio-processing presents an interesting method to alter the structure of BSG, rendering it a possible novel food ingredient to increase the nutrient capacity of products along with improving sustainability in brewing. Three different types of BSG were treated with a xylanase enzyme and separate LAB strains in various combinations. In order
to understand the effect of the several treatments, a detailed study of the general microstructure of BSG was conducted. All sample types were studied for microstructural changes... (More)
Spent grain (BSG) is the solid residue obtained during brewing containing leftover
malt and adjuncts. Though nutrient-dense, it is found to negatively impact texture and colour when used its raw form as an ingredient in food. Bio-processing presents an interesting method to alter the structure of BSG, rendering it a possible novel food ingredient to increase the nutrient capacity of products along with improving sustainability in brewing. Three different types of BSG were treated with a xylanase enzyme and separate LAB strains in various combinations. In order
to understand the effect of the several treatments, a detailed study of the general microstructure of BSG was conducted. All sample types were studied for microstructural changes using both CLSM and light microscopy after staining. Micrographs obtained showed that most effective microstructural degradation was seen at higher temperatures when enzyme treatment was followed by LAB fermentation by the A16 LAB strain. Attempts were also made to analyze EPS slime formation
by certain LAB strains on BSG and its characteristics. Light microscopy proved to be most effective in this case. A general comparison of the effectiveness of the two microscopy methods was done to conclude the study. (Less)
Popular Abstract
With growing consumer knowledge on health and nutrition, grains such as barley
have been gaining consumer acknowledgement and interest as a food ingredient.A
main constituent in brewing, barley has a high content of β-glucan and a considerable concentration of starch,protein, vitamins and other components of nutritional importance.
Though one of the most popular and heavily consumed beverages today, beer and
brewing processes still have a long way to go in terms of environmental consciousness,sustainability and minimal waste generation. Spent grain (BSG) is a collective term that includes barley grain husks and adjuncts obtained as solid residue during brewing. Currently, it accounts for more than 85% of the waste generated by... (More)
With growing consumer knowledge on health and nutrition, grains such as barley
have been gaining consumer acknowledgement and interest as a food ingredient.A
main constituent in brewing, barley has a high content of β-glucan and a considerable concentration of starch,protein, vitamins and other components of nutritional importance.
Though one of the most popular and heavily consumed beverages today, beer and
brewing processes still have a long way to go in terms of environmental consciousness,sustainability and minimal waste generation. Spent grain (BSG) is a collective term that includes barley grain husks and adjuncts obtained as solid residue during brewing. Currently, it accounts for more than 85% of the waste generated by breweries.Several studies have been conducted previously where BSG has been used as an ingredient in products such as bread, cakes and muns. However, the success of these were limited as BSG was found to signicantly alter the nal colour and texture. Altering the micro-structure could result in a product that is milder and malleable in terms of utility.
Bio-processing represents the industrial practice of biotechnology,using cell or enzyme systems to produce new substances reactions that would modify natural substances.It presents an interesting approach towards changing the micro-structure
of BSG.To test the effectiveness of any particular bio-processing technique in the
sample of interest, micro-structure study is crucial.
BSG samples processed in different conditions were frozen in liquid nitrogen and
sectioned onto microscope slides.These were then labelled using specic antibodies
for confocal laser scanning microscopy(CLSM, a type of fluorescence microscopy).
A liquid stain solution mixture was used to visualize starch and proteins in the BSG using light microscopy. The effect of different temperatures on enzyme treatment were also analyzed. Based on comparative study, optimal micro-structural degradation was observed in samples treated with a combination of enzyme treatment and lactic acid bacteria (LAB) fermentation. Different staining and visualization techniques were also attempted to observe slime formation due to some LAB secretions using BSG as a substrate. Light microscopy was understood to be most effective in visualizing the slime.More studies need to be conducted within this space. (Less)
Please use this url to cite or link to this publication:
author
Jacob, Sera Susan LU
supervisor
organization
course
KLGM01 20191
year
type
H2 - Master's Degree (Two Years)
subject
keywords
microstructure, CLSM, immuno-labelling, β- glucan, arabinoxylan, cell wall, EPS, food technology, livsmedelsteknologi
publication/series
Master Thesis
language
English
id
8992319
date added to LUP
2019-09-12 14:34:45
date last changed
2019-09-12 14:34:45
@misc{8992319,
  abstract     = {{Spent grain (BSG) is the solid residue obtained during brewing containing leftover
malt and adjuncts. Though nutrient-dense, it is found to negatively impact texture and colour when used its raw form as an ingredient in food. Bio-processing presents an interesting method to alter the structure of BSG, rendering it a possible novel food ingredient to increase the nutrient capacity of products along with improving sustainability in brewing. Three different types of BSG were treated with a xylanase enzyme and separate LAB strains in various combinations. In order
to understand the effect of the several treatments, a detailed study of the general microstructure of BSG was conducted. All sample types were studied for microstructural changes using both CLSM and light microscopy after staining. Micrographs obtained showed that most effective microstructural degradation was seen at higher temperatures when enzyme treatment was followed by LAB fermentation by the A16 LAB strain. Attempts were also made to analyze EPS slime formation
by certain LAB strains on BSG and its characteristics. Light microscopy proved to be most effective in this case. A general comparison of the effectiveness of the two microscopy methods was done to conclude the study.}},
  author       = {{Jacob, Sera Susan}},
  language     = {{eng}},
  note         = {{Student Paper}},
  series       = {{Master Thesis}},
  title        = {{Developing microscopy methods for evaluating bio-processed Brewers Spent Grain (BSG)}},
  year         = {{2019}},
}