Consumer and technological insights for improving the quality of osmo-dehydrated mango

Ita Sulistyawati

Research output: Thesisinternal PhD, WU

Abstract

Processing of mango can alter consumers’ perception of the final dried mango quality. To optimize the dried mango quality by product and process design, consumer’s insights on perceived product quality should be taken into account. The insights, which can consist of both product and process characteristics, should be transformed into useful input for designing food products. Previous consumer perception studies were focused on sensory, convenience and health aspects, and their interrelation with consumer perception, but less on that of process, particularly processing technology. No studies taking into account various drying technologies and the pre-treatments which can differently affect the intrinsic characteristics of dried mango and thus consumer perception. This thesis aimed at exploring insights from consumers and connecting them to technological optimization of the product quality during product and process design of dried mango.

Exploration of consumers’ health perception across cultures and demonstration of its relevance for product and process design in the early stages of new product development was studied using dried mango as a case. A focus group approach was used with participants from three countries (The Netherlands, China, and Indonesia). Themes relating to health perception emerged, namely nutrition, naturalness, taste, and wellbeing, which were all expressed on different levels of abstractness. Participants’ health perception of dried mango varied and is related to the product category with which it is compared, e.g. candy or fresh fruit; and the eating context, e.g. position in the diet either as a snack or a meal. Additionally, it was shown that consumer insights in the health perception of a product not only relate to product characteristics but also processing and its characteristics. These insights were applied to product and process design through iterative interdisciplinary interactions between consumer scientists and food technologists. The transformation of consumers’ perception into technical product and process specifications was demonstrated through an illustrative example of two product concepts of natural dried mango. This result suggests that iterative interactions are necessary to obtain relevant product and process characteristics in the simultaneous design of the technical product and process specifications based on consumer perceptions.

The perception of key intrinsic quality attributes and preferences of dried mango between consumers with different familiarity and health consciousness was further studied using an Adaptive Choice-Based Conjoint Analysis. This study involved respondents from three countries (The Netherlands, China, and Indonesia). Texture, taste and colour preferences of dried mango attributes differed between the three countries studied. The most important attribute for the Dutch and Chinese respondents was ‘free from extra ingredients’ as they preferred a “more pure” mango product. While Indonesians considered texture as the most important attribute preferring a crispier dried mango product. Familiarity with dried mango and health consciousness do not influence consumer preference of intrinsic attributes of dried mango. Different preferences of intrinsic attributes of dried mango between the studied respondent groups are related to cultural differences.

Effects of pretreatments with vacuum impregnation (VI) and high pressure (HP) and adding pectin methylesterase (PME) with calcium on the quality of osmo-dehydrated mango (Mangifera indica var. Kent) of different ripeness were studied. The use of unripe mango in OD showed two to five-fold higher soluble solid gain (SSG) compared to ripe mango for all treatments. Unripe mango pretreated with OD-VI showed the lowest water loss (WL) and the highest SSG. The OD-HP treatment had a similar but less pronounced effect as OD-VI on the parameters WL and SSG. The addition of the cell wall modifying enzyme PME increased OD efficiency for the treatments high pressure as well as vacuum impregnation, but only for ripe mango. Colour is an important quality attribute for dried mango. Overall, the applied settings for OD treatments appeared to be suitable for the preservation of the colour quality of mango. The hue (h*) values were generally preserved and colour intensity (C*) was maintained or only slightly increased in both ripeness in all treatments. Lightness (L*) was greatly reduced in unripe mango but stable in ripe mango. In general, adding PME increases a bit more effect on texture in terms of firmness and work of shear. This study thus demonstrates that using different ripeness of mango resulted in different quality of osmo-dehydrated mango upon pretreatments with calcium.

As a follow-up study, the effects of vacuum impregnation (VI) pretreatment and PME addition on the kinetics of mass transfer and vitamin C loss was studied during osmotic dehydration of mango. The water loss (WL) and weight reduction (WR) were modelled by the Weibull’s model, while soluble solid gain (SSG) was better described by Peleg’s model. VI increases soluble solid gain (SSG) indicated by a 55% lower value of the equilibrium constant (k2) in the Peleg model. Vitamin C loss was described by a multiresponse model incorporating both degradation and leaching processes into the osmotic solution (OS). Degradation was found to be the most important mechanism during osmo-dehydration of mango. The pretreatments have no significant effect on degradation and leaching rate constants of vitamin C. The combined modelling of the mass transfer and vitamin C retention was shown to be valuable in optimizing the OD process design to improve the health-promoting value of OD mango (e.g. sugar content, vitamin C) and reduce the processing time.

Furthermore, the results of this research highlight that taking into account both the consumer and technological insights is useful to optimize product and process design of dried mango with the desired quality.

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Fogliano, Vincenzo, Promotor
  • Dekker, Matthijs, Co-promotor
  • Verkerk, Ruud, Co-promotor
Award date20 May 2020
Place of PublicationWageningen
Publisher
Print ISBNs9789463953368
DOIs
Publication statusPublished - 2020

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