Use of natural low-methoxyl pectin from sunflower by-products for the formulation of low-sucrose strawberry jams

Abstract

Background: Due to the increasing incidence of obesity and cardiovascular diseases, consumers are demanding products with lower sugar content. In this sense, the reformulation of traditional foods with improved, safe and tasty ingredients is arousing a huge interest. Jams are conventionally produced with elevated amounts of sucrose, which increase the glycaemic index and must be avoided in certain kinds of consumers.

Results: This paper describes for the first time the elaboration of strawberry jams using low-methoxyl pectins from sunflower by-products, which allowed the addition of low amounts of sucrose (10-30%). These jams were compared with best-selling commercial samples. An in-depth physicochemical, compositional, sensorial and rheological characterization was carried out. The obtained jams were safe considering a_w and pH values; samples presented enough acidity to avoid microorganism development and syneresis. The stabilizing role of sunflower pectin is noteworthy in terms of colour and other physicochemical characteristics. The organoleptic analysis showed that the taste and sweetness of laboratory samples were highly valued, although the presence of pieces of fruits was disliked some panellists. After knowing the content of added sugar used in each jam, the tasters preferred samples with 20% and 30% of sucrose over commercial samples.

Conclusions: The results show the usefulness of sunflower pectin for the elaboration of jams of low glycaemic index. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: consumer acceptability; low-methoxyl sunflower pectin; low-sugar-added jam; rheological properties; sensory properties.

Figure 1

Study of gel strength of manufactured strawberry jams with reduced content of sugar using LMP pectin: (a) J‐10%S; (b) J‐20%S; (c) J‐30%S; and commercial jams using HMP pectin: (d) J‐Com‐1; (e) J‐Com‐2.

Figure 2

Sensory evaluation of strawberry jams analysed considering ‘just‐about right’ (JAR) scale for each attribute.

Figure 3

Penalty analysis. Representation of significant penalties (drops in liking) by proportion of panellists. The cut‐off point was 20% of consumers stating that one attribute was ‘not enough’ (−) or ‘too much’ (+). Attributes scored as ‘not enough’ are shown in red and attributes scored as ‘too much’ are shown in blue.