The Pinaceae species, flavor attributes for new culinary spices

21 Sep The Pinaceae species, flavor attributes for new culinary spices

Nabila Rodríguez Valerón1, Diego Prado Vásquez1, Rasmus Munk1

1 Alchemist Explore, Research and Development, Alchemist Aps, Refshalevej 173C, 1432 København, Danmark.

 

Abstract: The Pinaceae family has traditionally been used as medicine, resorted to as a famine food and for ornamental purposes – as Christmas trees. In the last few years numerous restaurants have been using different species of Pinaceae family as a garnish or an aromatic spice, using them in different culinary applications like oils and infusions to flavor dressings and broths. The main compounds in Pinaceae family are monoterpenes, oxygenated monoterpenes, sesquiterpenes, oxygenate sesquiterpenes, diterpenes and hydrocarbons, especially α-β-pinene, limonene, α- terpinene, and even bornyl acetate, responsible for aroma compounds such as citrusy-, woody-, herbal-, or piney aromas. According to the bibliography of the aroma compounds, 33 different attributes were chosen for a sensory analysis – with the goal of relating the attributes to the different Pinaceae samples. The statistical method Check–all-that-apply (CATA) was used to perform this research, and a parametric test was made for the first and second experiment, respectively. The attributes acidic, dark and light color, intense flavor, grapefruit flavor and citrus flavor presented a significant difference between samples. According to a correspondence analysis, citrus, intense, and grapefruit flavor attributes are related to Abies grandis, while dark color and even bitterness is related with Pseudotsuga menziesii. Finally, Picea abies is related to light color and sweetness. According to the CATA-results an ice cream and a cocktail were developed to carry out the second experiment. 

Since there was no significant difference between the samples, the p-value being higher than the significance level (p=0.05), the null hypothesis was accepted (the variances are identical). Despite that, when it came to an average liking, Abies grandis obtained a slightly higher score, followed by Picea abies and Pseudotsuga menziesii. This research thus gives a clearer idea about how to use these 3 types of Pinaceae family according to their sensory characteristics.

 

Keywords: spruce, CATA, sensory analysis, ingredient, Pinaceae, Spruce, Fir

 

Introduction

 

The Pineaceae family species from the genus Abies, Pseudotsuga and Picea have been used as Christmas trees in North America (Farjon, 2010), in traditional medicine as a rinse for sore and infected eyes, as a liquid to gargle for sore throats and a decoction of the leaves has been used as a tonic for treating colds (Moerman, 1998).  Pine wood, specially Pinus sylvestris L. (a typical Euro-Siberian species) is used as building material for structures, such as furniture, posts, and roof shingles, in different countries (Batsatsashvili et al., 2016; Kozakiewicz et al., 2020). 

As for culinary uses, the Pinaceae family has mainly been regarded as a famine food. The inner bark can be eaten and is cooked, usually dried, and then ground into a powder used as a thickening in soups or mixed with cereals for making bread (Yanovsky, 1936). The bark has mainly been harvested in the spring when rich and juicy (Weiner, 1990). Young shoot tips are used as a tea substitute (Moerman, 1998) (Facciola, 1990). Different parts of pine trees (Pinus spp.) like pinecones, from Pinus kochiana,  have been used for local people in Armenia, Eastern Europe, Russia and Georgia to make syrup and confiture (Batsatsashvili et al., 2016; Gerginova, Dimova, & Simova, 2017). Also, Pinus pinea, have traditionally been used for the production of pine nuts in Mediterranean countries like Italy, Turkey, Spain and Portugal (United Nations, 2013). The leaves have also been used in culinary applications such as oils and garnishes (Luis Aduriz, 2004).

Shoots from Pseudotsuga menziesii (Douglas fir) (Figure 1), and Picea abies (European spruce) (Figure 2) are used in contemporary cuisine. They can be served raw as garnish or as an aromatic spice in different culinary applications like oils and infusions for dressings and broths (Redzepi, 2010). The organoleptic profile of Pseudotsuga menziesii is mainly made up of monoterpenes such as (Z) and (E)-β-ocimene (green, woody, tropical), β-pinene (piney, woody, terpenic), sabinene, α-terpinolene (woody, terpenic, citrus), α-terpineol (woody, earthy, cooling), ꝩ-terpinene (citrus, terpenic), limonene (citrus, herbal, terpenic) or geranyl acetate (fruity, floral, rose) and cintronellyl acetate (Jirovetz, Puschmann, Stojanova, Metodiev, & Buchbauer, 2000; McGee, 2020). Onw the other hand, the organoleptic profile of Picea abies is made up of a different concentration of monoterpenes, oxygenated monoterpenes, sesquiterpenes, oxygenate sesquiterpenes, diterpenes and hydrocarbons (Haman, Morozova, Tonon, Scampicchio, & Ferrentino, 2019). Volatile compounds such as α-β-pinene, limonene, ρ-cymene (woody, terpenic, harsh), (E)- caryophyllene (woody, camphoric, peppery), δ-cadinene (woody), bornyl acetate (camphor, woody, pine), β-phellandrene (green and terpenic) or δ-3-carene  (citrus) are responsible of characteristic aromas of this species of spruce (Haman et al., 2019; McGee, 2020).

In recent years Abies grandis (Grand fir) (Figure 3), commonly called “grapefruit pine”, has been introduced in restaurant kitchens as an aromatic spice because of its distinct grapefruit flavors and it is availability all year around (Laursen, 2019).

Abies grandis contains a complex mixture of monoterpenes, sesquiterpenes and diterpenoid acids, used to deter insect pests and their symbiotic fungal pathogens (Phillips & Croteau, 1999). In previous research, it was shown that the leaf oil of Abies grandis is dominated by β-pinene (20.3 – 31%), responsible for piney, woody flavor; bornyl acetate (12.7 – 26.2%), for balsamic aroma and camphoreous flavor; β-phellandrene (13.7 – 25.2%), responsible for minty odor; and camphene (8.3 – 11.5%), giving a woody, fir needle aroma and camphereous, minty, green, spicy flavor, with moderate amounts of α-pinene (4.4 – 7.4%), responsible for herbal, pine, fresh odor and woody, tropical flavors; α-terpinene (1.1 – 2.2%), responsible for woody, citrus odor and terpenic, citrus, lemon and lime flavor; terpinolene (1.3 – 2.9%), giving an herbal, piney, citrus aroma and woody, lemon, lime and floral flavor; and α-terpineol (1.1 – 3.6%), responsible for terpenic, piney, citrus and floral odor, lemon, lime and woody flavors (Adams, Kauffmann, & Callahan, 2015; McGee, 2020; The Good Scents Company (tgsc), n.d.). 

The present study was aimed to determine the relationship between descriptors in three different species of Pinaceae, such as Picea abies, Abies grandis, and Pseudotsuga menziesii  applying check-all-that-apply (CATA) test. Two different culinary applications were prepared based on the descriptors chosen from CATA, after that a liking-test was conducted to identify which application that would be more appropriate for each Pinaceae species.

 

 

 

 

 

 

 

 

Material and Method

 

Material
With the aim of characterizing and studying the Abies grandis species, three different species of Pinaceae, one spruce and two firs were used for this research, including Picea abies and Pseudotsuga menziesii. The sample branches were collected during spring in Nordskovens Hundeskov, Silkeborg Minicipality, Denmark and kept at 4 ⁰C. Green meadow organic vodka of 40 % (v/v) of ethanol from Vintre Moller, Denmark, whole milk pasteurized with 3.5 % (w/v) of fat, heavy cream with 35 % (w/w), skimmed milk powder, dextrose, sucrose, inverted sugar, stabilizer (Cremodan Coldline) and tonic water were used for the study.

 

Samples for taste evaluation

• Cocktail preparation

Three samples of Pinaceae spirit were made with 10 % (w/v) of each species and vodka of 40 % (v/v). Vodka and clean leaves were blended with a food blender (Thermomix TM6) at 10700 r.p.m (speed 10) during 3 min. The aroma distillation was made with a rotary evaporator (Hei-Vap Core) at 45 ⁰C, 90 mba, 85 r.p.m for 3 h (Silori, Kushwaha, & Kumar, 2019). The cocktail was prepared according to Difford’s guide – Cocktails (without garnish) with 30 % (v/v) of Pinaceae spirit (40 % Abv) and 70 % (v/v) of tonic water (Erasmus bond, Classic Tonic Water) for each sample (Figure 2) (Simon Difford, 2013). 

 

 

 

• Ice cream preparation 

The ice cream was made according to Angelo Corvitto’s “white cream” ice cream base formula, with 56.7 % (v/w) whole milk, 17.2 % (v/w) heavy cream, 4.2 % (w/w) skimmed milk powder, 13.7 % (w/w) dextrose, 2.6 % (w/w) inverted sugar, 5.0 % (w/w) sucrose, and 0.6 % (w/w) stabilizer (Corvitto, 2011).

The whole milk and heavy cream were infused with 10 % (w/v) of each Pinaceae, for 12 h at 4 ⁰C in vacuum bags. After infusion, the milk and cream were filtered and mixed with milk powder and dextrose. The mix was heated to 40 ⁰C and half of the stabilizer was added with half of the sucrose. The rest of the stabilizer was added together with the inverted sugar. It was then stirred with a manual whisk and the mixture was heated to 85 ⁰C for at least one minute. The mixture was cooled down very quickly to 4 ⁰C and kept for 6-12 h to mature. Finally, it was homogenized with a hand blender, before being churned and frozen to -18  ⁰C (Corvitto, 2011) (Figure 3).

 

Consumer taste evaluation
The study was conducted with 80 culinary students from Copenhagen Hospitality College (HRS) from Copenhagen, Denmark and chefs from restaurant Alchemist, in a gender ratio of 51 % male and 49 % female. All of them were in a wide age range from 16 to 46 years old (averaging 23 years). The sensory analysis room was kept at 25⁰C and none of the consumers had taste disorders. 

 

Taste evaluation procedure
Check-all-that-apply (CATA) was used for data analysis in the first part of the taste evaluation. The questionnaire contained 33 different adjectives, according to the organoleptic profiles for each selected species of Pinaceae after studying published articles (Jaeger et al., 2015). Each sample was served in a sufficient amount to allow 2-3 bites per sample (5 cm approximately) and each of them (15 g of ice cream and 20 mL of gin tonic), were randomly coded. 

The second part of the taste evaluation was done by hedonic taste (liking), tasting two different recipes (previously explained) for each selected species. A scale from 1 (dislike extremely) to 9 (like extremely) was used to study if there were significant differences between the samples, to decide which recipe and technique was appropriate to reflect the positive aromatic characteristics of Abies grandis. Small plastic containers were used for each sample and coded randomly. 

 

Data analysis
Data was analyzed using Cochran’s Q test with pairwise comparisons approach based on the McNemar-Bonferroni to identify significant differences between attributes associated with each sample for the first part of the study (Meyners, Castura, & Carr, 2013). The second part of the analysis was carried out by the parametric test procedure for hedonic consumer data analysis (Bayarri, Martí, Carbonell, & Costell, 2012) to identify significant differences among species and recipe. Statistical analysis was performed by XLSTAT Version 2020.4.1. The analysis plot was created with the result from a contingency table, included in the results section.

 

Results

Experiment 1
Three different samples of Pinaceae were studied by CATA (Check-all-that-apply), with 33 different attributes from previous research. Sample one: Pseudotsuga menziesii, sample two: Picea abies and sample three: Abies grandis. 

All the samples were analysed by Cochran’s Q test and significant differences were detected in almost all the attributes associated with each sample as Table 1 shows. According to the test, six of the 33 attributes were significantly different. Table 1 shows those attributes that show a difference between samples, such as light color for sample two (Picea abies). On the other hand, the attribute citrus shows significant difference between Abies grandis regarding Pseudotsuga menziesii and Picea abies.

Regarding the correspondence analysis plot (Figure 6) shown F1 (68.44 %) and F2 (31.56 %), which the data variability is explained with 100%. As shown F1, Pseudotsuga menziesii and Abies grandis seem to be closely related in regard to some of the attributes, such as citric or dark color as shown in Figure 6. On the contrary, Picea abies seem to be closely related to attributes such as crunchy, sweet, or earthy although the relation is not significant. The second experiment was based on the results obtained from this experiment. All the terms used as attributes in this experiment, are shown in Table 2. 

 

Table 1. Results of Cochran’s Q test for each attribute.

Attributes	1	2	3	p-values
A1	0.488 (a)	0.525 (a)	0.613 (a)	0.166
A2	0.175 (a)	0.200 (a)	0.225 (a)	0.687
A3	0.175 (a)	0.200 (a)	0.213 (a)	0.804
A4	0.713 (a)	0.588 (a)	0.675 (a)	0.206
A5	0.025 (a)	0.025 (a)	0.113 (a)	0.017
A6	0.313 (a)	0.488 (ab)	0.613 (b)	0.000
A7	0.063 (a)	0.063 (a)	0.025 (a)	0.472
A8	0.488 (b)	0.113 (a)	0.400 (b)	< 0.0001
A9	0.175 (a)	0.213 (a)	0.213 (a)	0.755
A10	0.375 (ab)	0.275 (a)	0.475 (b)	0.029
A11	0.288 (a)	0.238 (a)	0.200 (a)	0.337
A12	0.288 (a)	0.213 (a)	0.275 (a)	0.469
A13	0.300 (a)	0.225 (a)	0.200 (a)	0.273
A14	0.425 (a)	0.488 (a)	0.400 (a)	0.465
A15	0.238 (a)	0.363 (a)	0.325 (a)	0.193
A16	0.213 (ab)	0.088 (a)	0.288 (b)	0.002
A17	0.388 (a)	0.425 (a)	0.500 (a)	0.262
A18	0.138 (a)	0.225 (a)	0.213 (a)	0.179
A19	0.050 (a)	0.088 (a)	0.138 (a)	0.143
A20	0.100 (a)	0.488 (b)	0.088 (a)	< 0.0001
A21	0.113 (a)	0.150 (a)	0.050 (a)	0.108
A22	0.300 (a)	0.200 (a)	0.338 (a)	0.116
A23	0.288 (a)	0.263 (a)	0.250 (a)	0.839
A24	0.213 (a)	0.113 (a)	0.138 (a)	0.104
A25	0.350 (a)	0.238 (a)	0.575 (b)	< 0.0001
A26	0.238 (a)	0.163 (a)	0.175 (a)	0.391
A27	0.063 (a)	0.088 (a)	0.113 (a)	0.494
A28	0.063 (a)	0.088 (a)	0.138 (a)	0.247
A29	0.125 (a)	0.138 (a)	0.063 (a)	0.260
A30	0.113 (a)	0.088 (a)	0.150 (a)	0.453
A31	0.150 (a)	0.225 (a)	0.250 (a)	0.166
A32	0.125 (a)	0.100 (a)	0.088 (a)	0.705
A33	0.075 (a)	0.050 (a)	0.063 (a)	0.779

 

Table 2. Terms used for describing all attributes in each sample.

Attribute	Code	Attribute	Code	Attribute	Code
Dry	A1	Not sweet	A12	Herbal flavour	A23
Juicy	A2	Not salty	A13	Oily	A24
Sweet	A3	Woody	A14	Citrus	A25
Bitter	A4	Earthy	A15	Natural	A26
Salty	A5	Grapefruit flavour	A16	Artificial	A27
Acidic	A6	Aftertaste	A17	Not bitter	A28
No aftertaste	A7	Astringent	A18	Not acidic	A29
Dark colour	A8	Soft	A19	Not woody	A30
Crunchy	A9	Light colour	A20	Floral flavour	A31
Intense flavour	A10	Mild taste	A21	Not earthy	A32
Hard	A11	Fruity flavour	A22	Not astringent	A33

 

 

 

Experiment 2

The second experiment consisted of making two different recipes, emphasizing the attributes that presented a significant difference. The preparations, cocktail and ice cream, were made as explained in the method section, and data was analysed by variance analysis for k-samples.

According to the results obtained by variance analysis for the ice cream samples and p-values, there are no significant differences between the samples of ice cream and cocktail. Despite that the Pinaceae family presented a significant difference in attributes between the samples during the first experiment, in this experiment the null hypothesis is accepted due to that the variances are identical. Overall, the results on liking were close to each other, but the samples with Abies grandis showed the highest scores followed by Picea abies and Pseudotsuga menziesii for cocktail and ice cream as shown in Table 3.

 

Table 3. Average liking on the scale from 1 to 9 in ice cream and gin tonic per each sample of spruce and p-value.

Pinaceae	Ice cream	Mean	Cocktail	Mean
Picea abies	109	4.687	230	4.855
Pseudotsuga menziesii	612	4.072	851	4.506
Abies grandis	534	4.759	467	5.048
	p- value	0.366		0.102

 

Discussion and conclusion

The present study has shown how the three different samples of the Pinaceae species have different aroma profiles. According to the results, Abies grandis is aromatically related to Pseudotsuga menziesii. The citrus attribute is common in both samples, but is perceived with more intensity in Abies grandis (Adams et al., 2015) than in Pseudotsuga menziesii because these citrus compounds are more pronounced in young leaves for this species, like the sample used (Maarse & Kepner, 1970). Following the results obtained for Pseudotsuga menziesii the species is related to natural, dark colour, not astringent, bitterness. These attributes might be related to the concentration of terpenes such as α-pinene, phellandrene, or sabinene (Jirovetz et al., 2000; Won & Hyung, 2005). In Abies grandis some of the attributes found were citrusy, intense flavor, grapefruit flavor (as its common name), and not woody. These attributes might be related to the concentration of different terpenes such as limonene, β-pinene, sabinene or camphene. Despite the concentration of bornyl acetate, a compound highly related to the woody attribute, not woody was the most selected attribute (Won & Hyung, 2005). 

On the other hand, Picea abies attributes contrast completely with the other species as shown in the symmetric plot (Figure 6). This result is in line with what was expected, because of the different aroma profile as demonstrated in research conducted by Nabil Haman at Piazza University (Haman et al., 2019). 

Astringin is one of the molecules in major concentration (typical in this species), directly related to astringency in these samples. Also, the concentration of cinnamon acid (responsible for cinnamon aroma) or ferulic acid (responsible for vanilla aroma) (Pérez-Rodríguez, Pinheiro de Souza Oliveira, Torrado Agrasar, & Domínguez, 2016) might be closely related to sweetness. 

As previously mentioned, the second experiment was performed using two different recipes according to the results from our first experiments. The two recipes have not shown a significant difference, and consequently concerning these specific recipes it is possible to use all species, but there is a slight difference of the level of liking between them. Abies grandis has the highest score for both recipes, 5.048 for the cocktail, followed by Picea abies and Pseudotsuga menziesii. For the ice cream the average liking is 4.759 for Abies grandis, followed by Picea abies and Pseudotsuga menziesii as is shown in Table 3. The reason that Pseudotsuga menziesii is less liked by consumers might be related to bitterness (Figure 6). Also, the acceptance of Abies grandis in both recipes might be relate to citrus flavour, due to it already being more accepted by the consumers (Beauchamp & Jiang, 2015). 

 

In conclusion this research has demonstrated that these three Pinaceae species have different sensory attributes. Abies grandis is associated with citrus and grapefruit flavour, intense flavour and not woody, while Pseudotsuga menziesii is related to natural, dark colour, not astringent and bitterness attributes. Finally, the main attributes for Picea abies are astringent and sweet (Table 4). Regarding the chosen recipes, no significant differences were found between species. According to this specific methodology, it is possible to use any Pinaceae species presented in this article as all of them will add a specific flavour profile to the recipe – but does not significantly affect the level of liking among consumers.

 

This study shows that each Pinaceae species need to be considered as having individual organoleptic characteristics, and not just be lumped together as a generic aroma profile. This way chefs can use them in culinary ways that highlight their specific attributes.  

The quantification of aroma with the chromatography method in different seasons and maturation levels of these Pinaceae species and comparing them to consumer likeability might be a relevant future line of research to further understand this type of new ingredients role in gastronomy as a culinary spice.

 

Acknowledgement

We thank Copenhagen Hospitality College (HRS) for providing their space and students for the sensory analysis and Thomas Laursen (Wildfooding) for providing the Pinaceae samples.

 

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«File:Abies grandis 001.jpg» by Krzysztof Golik is licensed with CC BY-SA 4.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/4.0

 

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