1. The study evaluated the ensiling process of carrot by-products with or without commercial silage additives to determine effects on chemical composition, fermentation, and aerobic stability. 2. Carrot by-products were ensiled with one of three treatments: a control without additives, an inoculant of lactic acid bacteria, or formic acid. 3. The results showed that formic acid was most effective at restricting spontaneous fermentation and improving aerobic stability, while both additives benefited the ensiling process and preserved nutrient quality of the carrot by-products.

1. 0
100
200
300
400
500
600
Control LAB FA Control LAB FA
Carrot with pieces Carrot without pieces
WSC
Crude protein
Ash
Carrot by-product fermentation
quality and aerobic stability could
be modified with silage additives
XVIII International Silage Conference, 24-26 July 2018, Bonn, Germany
M. Franco, T. Jalava, E. Järvenpää, M. Kahala, M. Rinne
Natural Resources Institute Finland (Luke), Finland
Correspondence: marcia.franco@luke.fi
Objective: to valuate the carrot by-product ensiling process with
or without commercial silage additives (lactic acid bacteria
inoculants and formic acid) on chemical composition,
fermentation pattern and aerobic stability
Materials and Methods
• 2 × 3 factorial - Two types of raw material:
Three additive treatments:
1. Control without additive
2. Heterofermentative lactic acid bacteria (LAB) inoculant
(Lactobacillus paracasei, L. plantarum, Lactococcus lactis and
L. buchneri, 1.25×1011 cfu/g; 2 g t-1)
3. Formic acid (FA) based product (76% FA, 5.5% ammonium
formate; 5 l t-1)
• The carrot mass was carefully mixed with the additive and
packed tightly in plastic bags (10 kg fresh matter)
• Two replicates per treatment were prepared
• Silos were opened after a three-week preservation period at
room temperature
• Aerobic stability was evaluated once daily by visually observing
growth of yeasts and moulds on the surface of the carrot mass.
Introduction
• Food industry needs to be more sustainable
• By-products as animal feeds offer many possibilities for circular
economy
• Challenge: how to preserve and store vegetable residues as
they are typically wet and prone to fast deterioration?
• Additives can be added to materials to preserve and/or
enhance the quality, such as increasing aerobic stability
Results
Figure 1 Dry matter, ammonia nitrogen (primary axis) and pH (secondary axis) of two
carrot by-product types ensiled with different additives.
Figure 4 Aerobic stability (days) of fresh and ensiled carrot by-products according to raw
material types and additive treatments.
Conclusions
• Preserving carrot by-products proved to be challenging. Spontaneous fermentation could efficiently be restricted with the use of FA and
benefits in aerobic stability were achieved
0
1
2
3
Control LAB FA Control LAB FA
Carrot with pieces Carrot without pieces
Aerobicstability,days
Fresh
Ensiled
3.5
3.6
3.7
3.8
0
25
50
75
100
125
150
175
Control LAB FA Control LAB FA
Carrot with pieces Carrot without pieces
Dry matter, g/kg
NH3-N, g/kg N
pH
Carrot with pieces Carrot without pieces
Control LAB FA Control LAB FA
Yeast <1.0×103
4.8×103
6.1×103
2.8×103
<1.0×103
<1.0×103
Mould <1.0×103
<1.0×103
<1.0×103
<1.0×103
<1.0×103
<1.0×103
Enterobacteria <1.0×101
<1.0×101
<1.0×101
<1.0×101
<1.0×101
<1.0×101
LAB 2.0×108
2.2×108
1.8×104
1.5×108
1.1×108
3.1×105
Table 1 Type of raw material and additive effects on hygienic quality (cfu/g) of ensiled
carrot by-products
Figure 2 Type of raw material and additive effects on chemical composition quality of
ensiled carrot by-products.
R C LAB C FA LAB FA
DM, g/kg 0.46 0.17 <0.01 <0.01
pH <0.01 0.73 <0.01 <0.01
NH3-N, g/kg N 0.51 0.82 <0.01 <0.01
R C LAB C FA LAB FA
Ash <0.01 0.47 <0.01 <0.01
CP 0.95 0.62 <0.01 <0.01
WSC <0.01 0.89 <0.01 <0.01
R C LAB C FA LAB FA
Lactic acid <0.01 0.98 <0.01 <0.01
Acetic acid <0.01 0.61 <0.01 <0.01
Propionic acid 0.03 0.92 <0.01 <0.01
Butyric acid 0.41 0.14 <0.01 <0.01
Weight loss, % 0.65 0.03 0.30 <0.01
Figure 3 Type of raw material and additive effects on fermentation quality of ensiled
carrot by-products.
0
50
100
150
200
250
Control
LAB
FA
Control
LAB
FA
Carrot with pieces Carrot without pieces
Acetic acid
Lactic acid
0
0.25
0.5
0.75
0
1
2
3
4
5
6
Control
LAB
FA
Control
LAB
FA
Carrot with pieces Carrot without
pieces
Butyric acid
Propionic acid
Weight loss, %
Carrot by-product with pieces Carrot by-product without pieces
Photos: ©Luke / Marketta Rinne
Photos: ©Luke / Taina Jalava