We are so happy and proud to announce our recent study which we did for Podravka “VEGETA BIO” and “PASSATA BIO RAJČICA” brands, the leading brand in terms of volume sales in the category of dehydrated (dry) food additives, been published in the top tier Journal Frontiers in Sustainable Food System and is available online (gold open access)!

This is the first study using remote eye tracking measurements to assess the underlying physiological responses of BIO-labelled products on consumer purchasing decisions. The aim of the current study was to observe whether the BIO label affects decision-making processes and if the color of the BIO packaging is important with the help of online webcam-based eye-tracking and facial coding.

Unlike traditional research methods used for investigating consumer responses to different stimuli such as surveys, interviews or focus groups, recently, the autonomic neuropsychological measures have been implemented within the neuromarketing field to obtain subconscious preferences from the consumer’s brain. In the current study, the webcam-based eye-tracking technology is used to analyze both visual and emotional reflects of the consumer green purchasing behavior, which has grown notably in the last decade. The main interest was to assess whether the color packaging affects the BIO label and if such a label is essential for consumers’ purchasing behavior. The packaging designs of the two-well known products from one of Croatia’s most prominent food processing companies were manipulated in packaging color and the BIO label placement. The results have shown that regardless of the package design and the placement of the BIO label, participants elicited higher intensities of negative emotion. The eye-tracking metrics showed that for both products the color of the packaging and the BIO label placement matter.

Materials and Methods

Images of the two well-known products from one of the biggest food processing companies in Croatia, Podravka, were used. The first product was the mashed tomato – Passata (original packaging of mashed tomato under the name „Podravka Passata, Istarska rajčica“), while the other was the mix of spices – Vegeta (Vegeta Original). Vegeta is used in cooking and it ranks first in terms of volume sales in the category of dehydrated food additives within 31 European countries.¹

Both of these products have the bio line (light brown color packaging with a prominent bio label; Vegeta Bio and BIO passata). In addition to the original bio packaging images (Figure 1a, 2a), two additional images were used in the study for each product. One image showed the actual color of the bio packaging but without the bio label (Figure 1b, 2b). In contrast, in the case of Vegeta, the other image consisted of the bio label and manipulated packaging color (Figure 2c), while in the case of Passata, the other image consisted of manipulated packaging color without the bio label (Figure 1c). In both cases, the manipulated color (blue) resembled the packaging color from the non-bio line. The color manipulation was done to assess whether the packaging color is crucial for consumers when deciding to purchase products with BIO label.

The online platform for advanced quantitative neuromarketing research, “Tobii Sticky,” was utilized for webcam-based eye tracking (15Hz) and facial coding to assess visual behavior and emotional reaction to the different product designs. Based on previous testing’s, Sticky’s average gaze error in a real-world environment is 1.6 to 1.8 degrees, equivalent to approximately 5% of the screen width and 7% of the screen height on a computer, which suffices this type of neuromarketing research for obtaining a robust outcome. Participants were given calibration instructions to ensure that the technical requirements were met before data collection. Since the study was conducted outside a controlled laboratory environment, there was no physical control over the ISO eye tracking standards. Hence, only recordings marked as “usable” in Tobii Sticky were used as they suggest that these participants met the technical requirements (i.e., proper lightning, controlled movement) entirely. At the end of the experiment, participants were also asked to answer questions assessing the likelihood of purchasing the product with the BIO label, the importance of the BIO label when deciding on what to purchase, and whether the color of the packaging and its design plays a role in their decision-making process (Table 4).


One hundred and sixty-eight participants from Croatia (18-65, both gender) were involved in the testing. 87 participants completed the entire experiment from which we get 33 usable recordings whose gaze and/or emotion was trackable during their session (ie. had proper lighting and did not move). 54 participants partially were involved in study (participants who started the experiment but closed the browser or had timed out before reaching the end), 1 participant was excluded from study and 26 where screen out (participants that ended their session based on a screen out question or did not meet technical requirements). To ensure that the desired level of power and significant results are achieved, the required sample size was calculated a priori using G*Power (Faul et al., 2009). Based on the G*Power output, a sample size of n = 84 was required to detect the effect with a power of 80% and a two-sided significance level of 5% (Supplementary Figure 1).

Tested subjects were recruited from the database of Podravka customers who regularly buy their products, as well as from the database of students of the Faculty of Food Technology and Biotechnology (students with a master’s degree in nutrition) in the Republic of Croatia. The age range of participants varied from 18 to 65 years. More than 60 percent of participants were 36-55, while the others were 18-35 years old. The majority of the participants were either entirely or partially responsible for procuring groceries in their households, while 3 participants were not.

Participation in the study was voluntary, and no incentives were given.

Following the European Code of Ethics for Research, all participants were informed about the study and gave their written, informed consent in digital form before taking part in the study. Otherwise, they were no able to participate. Participants’ data were treated according to standard practice and compliance with GDPR. The Ethics Committee of the Institute for Neuromarketing approved this research and supervised the study in order to be underlined with local and international ethical guidelines which are officially published at the official Institute’s website.

Statistical power analysis program G*Power (version was used for the calculation of the sample size (Faul et al., 2009) by use of the one-way analysis of variance (ANOVA) and fixed effects, using the F-test. Selected parameters used for the recall results were as follows: an average effect size f = 0.4; alpha (α) error probability = 0.05; power (1-β) = 0.95 for two groups. The calculation, based on the input parameters, required 84 subjects, but to avoid any losses (as failures in recording, not finishing the task), a minimum of 150 subjects was defined as the total sample, which resulting in a representative pool of 87 respondents who fully completed the survey.

The complete research was taken at the Institute for Neuromarketing, Zagreb, Croatia, which supported the research with neuromarketing equipment and data analysis. Therefore, we take this opportunity to thank the all authors Doc.Dr.sc. Hedda Martina Šola, Prof. Dr.sc. Jasenka Gajdoš Kljusurić, and Doc.Dr.sc Ivana Rončević who contributed to this research significantly and made it happen to be published in the top-tier journal Frontiers, as deserves! It is literally true how “talent wins games, but teamwork and intelligence win championships”.

To get access to full research, please visit HERE

Figure 1. Passata in original BIO packaging, sold in stores (a), original color combination but without the BIO label, not sold in stores (b), and manipulated color combination, not sold in stores (c).

Images copyright protected by Podravka. All manipulations with color and color inversions on products were made by Podravka exclusively for the purposes of this research.

Figure 2. Vegeta in original BIO packaging, sold in stores (a), original color combination but without the BIO label, not sold in stores (b), and manipulated color combination, not sold in stores (c).

Images copyright protected by Podravka. All manipulations with color and color inversions on products were made by Podravka exclusively for the purposes of this research.


1) This statement is based on Nielsen’s panel data from trade in 31 European countries (Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, the Czech Republic, Denmark, Estonia, France, Greece, Croatia, Ireland, Italy, Latvia, Lithuania, the Netherlands, Norway, Germany, Hungary, Poland, Portugal, Romania, Russia, Northern Macedonia, Slovakia, Slovenia, Serbia, Spain, Sweden, Switzerland and Ukraine), according to which Vegeta is the leading brand in terms of volume sales in the category dehydrated (dry) food additives in the period October 2020 – September 2021 (copyright © 2021, The Nielsen Company, all rights reserved). “Link: https://www.vegeta.hr/hr/aktualnosti/vegeta-najprodavaniji -dehydrated-food-supplement-in-Europe

2) Faul, F., Erdfelder, E., Buchner, A., & Lang, A.-G. (2009). Statistical power analyses using G*Power 3.1: Tests for correlation and regression analyses. Behav. Res. Methods 41, 1149-1160. doi: 10.3758/BRM.41.4.1149

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