Food Futures - esn-network.com · •Further analysis showed that the terpenoid content...
1
Food Futures Effects of High Pressure Processing on Sensory & Volatile Characteristics of Carrots Irene Baxter 1 , Dimitrios Zabaras 1 , Tiffany Bardelot 2 , Patrick O’Riordan 1 , Damian Frank 1 , & Ciarán Forde 1 1 CSIRO- Food Futures Flagship/Food Science Australia, North Ryde, Sydney, NSW, Australia 2 ENSBANA, Dijon, France. Introduction High pressure processing (HPP) uses pressure to extend food shelf life and improve microbial safety of foods. In this study, HPP at 600 MPa for 2 minutes was used to process solid carrots slices, which were then stored at 4°C. Carrot samples were analysed raw, steamed or cooked by microwave. Descriptive sensory analysis and Gas Chromatography-Olfactometry-Mass Spectrometry (GC-O-MS) were used to understand the influence of HPP on the organoleptic properties of carrots. Methods • Carrot samples were HPP at 600MPa for 2 minutes, then stored at 4°C until testing. • Samples were analysed raw or cooked. Three cooking methods were used: steaming for 20 mins, microwave for 4 mins, microwave for 7 mins. • Nine trained sensory judges assessed the sensory properties of the samples. • Volatile analysis was conducted by GC-O-MS, a GC-O panel was established (N=4) to profile the intensity of odour-active volatiles in control and HPP raw carrots. The effect of cooking treatment on the volatile flavour characteristics of carrots was not investigated. Control Steamed Control MW 7min Meaty odour Duration of aftertaste Control MW 4min Control Raw Flavour intensity Flexibility Bitter aftertaste Core colour Sourness Starchy odour HPP Steamed Sour aftertaste Chemical Processed Chemical aftertaste Processed odour Starchy Strong odour HPP MW 7min HPP MW 4min HPP Raw Chewing time Corn like Sweet corn odour Sweet aftertaste Sweet Surface moisture Naturalness Sweet odour Brightness Floral odour Grassy odour Visual firmness Tactile Firmness Grainy Crunchiness Flesh colour Sour odour -1.2 1.2 -1.2 1.2 Principal Component 1 (45%) Principal Component 1 (26%) Control Steamed Control MW 7min Meaty odour Duration of aftertaste Control MW 4min Control Raw Flavour intensity Flexibility Bitter aftertaste Core colour Sourness Starchy odour HPP Steamed Sour aftertaste Chemical Processed Chemical aftertaste Processed odour Starchy Strong odour HPP MW 7min HPP MW 4min HPP Raw Chewing time Corn like Sweet corn odour Sweet aftertaste Sweet Surface moisture Naturalness Sweet odour Brightness Floral odour Grassy odour Visual firmness Tactile Firmness Grainy Crunchiness Flesh colour Sour odour -1.2 1.2 -1.2 1.2 Principal Component 1 (45%) Principal Component 1 (26%) Results • PCA showed that HPP of carrots reduced sweetcorn odour, sweet flavour, corn-like flavour, sweet aftertaste, and natural appearance (Figure 1). • PCA also showed that HPP increased sour odour, chemical odour, sour flavour, processed flavour, sour aftertaste, bitter aftertaste, intensity of flesh colour, flexibility and chewing time in the carrots (Figure 1). • The aromagrams (Figures 2 & 3) show the perceptual differences between the samples during GC/MS-O, with the HPP sample having lower floral/herbaceous and nutty notes and higher bitter/citrus and oily notes than the control sample. • Further analysis showed that the terpenoid content (responsible for the characteristic aroma and flavour of carrots) of control and HPP carrots were similar. However, cell damage during HPP caused differences in the sugar content, which presumably affected organoleptic properties of the HPP carrots. Fig 1: Difference between Control and HPP samples ß-Pinene Limonene ß-Pinene Caryophyllene Hexanal α-farnesene p-cresol humulene Acetic acid ß-Pinene Limonene ß-Pinene Caryophyllene Hexanal α-farnesene p-cresol humulene Acetic acid Fig 2: GC/MS-O analysis - Control Aromagram Conclusions The bitterness perceived in the HPP samples by the sensory panel is likely to be due to loss of sugars from the cells during HPP. A synergistic effect whereby reduced sweetness increases perception of bitterness is plausible. Further work is on-going to examine the effects of HPP + cooking on organoleptic properties of carrots. The effect (if any) of HPP on the levels of the known bitter-tastants in carrots will also be examined. Hexanal Myrcene Limonene 1-octen-3-one 6 methyl-5-hepten-2- one Butanoic acid Hexanal Myrcene Limonene 1-octen-3-one 6 methyl-5-hepten-2- one Butanoic acid www.CSIRO.au/flagships Fig 3: GC/MS-O analysis - HPP Aromagram
Transcript of Food Futures - esn-network.com · •Further analysis showed that the terpenoid content...
Food FuturesEffects of High Pressure Processing on Sensory & Volatile
Characteristics of CarrotsIrene Baxter1, Dimitrios Zabaras1, Tiffany Bardelot2, Patrick O’Riordan1, Damian Frank1, & Ciarán Forde1
1 CSIRO- Food Futures Flagship/Food Science Australia, North Ryde, Sydney, NSW, Australia2ENSBANA, Dijon, France.
IntroductionHigh pressure processing (HPP) uses pressure to extend food shelf life and improve microbial safety of foods. In this study, HPP at 600 MPa for 2 minutes was used to process solid carrots slices, which were then stored at 4°C. Carrot samples were analysed raw, steamed or cooked by microwave. Descriptive sensory analysis and Gas Chromatography-Olfactometry-Mass Spectrometry (GC-O-MS) were used to understand the influence of HPP on the organoleptic properties of carrots.
Methods• Carrot samples were HPP at 600MPa for 2 minutes, then stored
at 4°C until testing.• Samples were analysed raw or cooked. Three cooking
methods were used: steaming for 20 mins, microwave for 4 mins, microwave for 7 mins.
• Nine trained sensory judges assessed the sensory properties of the samples.
• Volatile analysis was conducted by GC-O-MS, a GC-O panel was established (N=4) to profile the intensity of odour-active volatiles in control and HPP raw carrots. The effect of cooking treatment on the volatile flavour characteristics of carrots wasnot investigated.
Control Steamed
Control MW 7minMeaty odour
Duration of aftertaste
Control MW 4minControl Raw
Flavour intensity
FlexibilityBitter aftertaste
Core colourSourness
Starchy odourHPP SteamedSour aftertaste
Chemical
ProcessedChemical aftertaste
Processed odour
Starchy
Strong odour
HPP MW 7min
HPP MW 4minHPP Raw
Chewing time
Corn like
Sweet corn odour
Sweet aftertasteSweet
Surface moistureNaturalness
Sweet odour
BrightnessFloral odourGrassy odour
Visual firmnessTactile Firmness
GrainyCrunchiness
Flesh colourSour odour
-1.2
1.2
-1.2 1.2
Principal Component 1 (45%)
Prin
cipa
l Com
pone
nt 1
(26%
)
Control Steamed
Control MW 7minMeaty odour
Duration of aftertaste
Control MW 4minControl Raw
Flavour intensity
FlexibilityBitter aftertaste
Core colourSourness
Starchy odourHPP SteamedSour aftertaste
Chemical
ProcessedChemical aftertaste
Processed odour
Starchy
Strong odour
HPP MW 7min
HPP MW 4minHPP Raw
Chewing time
Corn like
Sweet corn odour
Sweet aftertasteSweet
Surface moistureNaturalness
Sweet odour
BrightnessFloral odourGrassy odour
Visual firmnessTactile Firmness
GrainyCrunchiness
Flesh colourSour odour
-1.2
1.2
-1.2 1.2
Principal Component 1 (45%)
Prin
cipa
l Com
pone
nt 1
(26%
)
Results
• PCA showed that HPP of carrots reduced sweetcorn odour, sweet flavour, corn-like flavour, sweet aftertaste, and natural appearance (Figure 1).
• PCA also showed that HPP increased sour odour, chemical odour, sour flavour, processed flavour, sour aftertaste, bitter aftertaste, intensity of flesh colour, flexibility and chewing time in the carrots (Figure 1).
• The aromagrams (Figures 2 & 3) show the perceptual differences between the samples during GC/MS-O, with the HPP sample having lower floral/herbaceous and nutty notes and higher bitter/citrus and oily notes than the control sample.
• Further analysis showed that the terpenoid content (responsible for the characteristic aroma and flavour of carrots) of control and HPP carrots were similar. However, cell damage during HPP caused differences in the sugar content, which presumably affected organoleptic properties of the HPP carrots.
Fig 1: Difference between Control and HPP samples
ß-Pinene
Limonene
ß-Pinene
Caryophyllene
Hexanal
α-farnesenep-cresol
humulene
Acetic acid
ß-Pinene
Limonene
ß-Pinene
Caryophyllene
Hexanal
α-farnesenep-cresol
humulene
Acetic acid
Fig 2: GC/MS-O analysis - Control Aromagram
Conclusions
The bitterness perceived in the HPP samples by the sensory panel is likely to be due to loss of sugars from the cells during HPP.
A synergistic effect whereby reduced sweetness increases perception of bitterness is plausible.
Further work is on-going to examine the effects of HPP + cooking on organoleptic properties of carrots. The effect (if any) of HPP on the levels of the known bitter-tastants in carrots will also be examined.
HexanalMyrcene
Limonene
1-octen-3-one
6 methyl-5-hepten-2-one
Butanoic acid
HexanalMyrcene
Limonene
1-octen-3-one
6 methyl-5-hepten-2-one
Butanoic acid
www.CSIRO.au/flagships
Fig 3: GC/MS-O analysis - HPP Aromagram
