Background: Why a low-sugar collagen jelly matters
Many adults aim to cut sugar for weight management, skin health, or glucose control, yet crave indulgent snacks that feel healthy. Collagen supports skin hydration and elasticity, while apples, carrots, and tomatoes deliver polyphenols, flavonoids, carotenoids, and fiber that combat daily oxidative stress from pollution, light exposure, and busy routines. Replacing sucrose with erythritol, a zero-glycemic polyol, helps lower post-meal glucose without added calories. The challenge lies in preserving color, texture, and mouthfeel when sugar is reduced. The study in Foods addresses this by identifying the right fruit-vegetable powder level to balance flavor, nutrition, and sensory appeal in a low-sugar jelly.
About the study: design and aims
Researchers crafted six collagen jelly formulations, each incorporating hot-air-dried apple, carrot, and tomato powders in a 5:1:1 weight ratio. Powder levels ranged from 0% to 10% of total mass (0, 2, 4, 6, 8, 10%). A composite gelling system—konjac glucomannan, locust bean gum, and κ-carrageenan (1:0.8:0.2, w/w/w)—formed the jelly structure. Sweetness came from an equal mix of sucrose and erythritol (8.5 g each per 100 g), with citric acid and salt to heighten flavor. The mixtures were heated, molded, and cooled to set, then analyzed for composition, color, texture, and antioxidant capacity.
What they measured: color, texture, sugars, and antioxidants
Color was tracked using Hunter L (lightness), a (red-green), and b (yellow-blue) values. Texture analysis assessed hardness, adhesiveness, cohesiveness, springiness, gumminess, and chewiness. Sugar content was expressed as degrees Brix, while basic nutrients (moisture, protein, fat, ash, carbohydrates) were determined by standard methods. Antioxidant capacity was evaluated via Total Flavonoid Content (TFC), Total Polyphenol Content (TPC), and radical-scavenging assays (DPPH and ABTS), all converted to vitamin C equivalents for comparability. A 30-person sensory panel evaluated color, odor, taste, texture, and overall liking on a seven-point scale. Statistical testing confirmed significant differences across formulations.
Key findings: color, texture, and nutrition rise with powder
As fruit-vegetable powder increased, color deepened: lightness dropped (L from 34.83 to 23.60), while redness and yellowness rose (a from −1.45 to 18.93; b from 2.48 to 25.59). This warmer hue aligns with consumer expectations for fruit-forward products and signals enhanced fruit character.
Nutritionally, moisture declined with more powder (≈50.9% to 39.7%), while protein, fat, and ash modestly rose. Carbohydrates climbed to about 49.8% at 10%, yet the product remained “low-sugar”: Brix rose only from 2.43 to 3.63, far below typical sucrose-sweetened desserts (often 21–23 °Brix). This is meaningful for glucose-conscious consumers seeking a dessert-like treat without a sugar burden.
Texture shifted with powder load: hardness increased (1.32 N to 3.39 N), adhesiveness rose at higher levels, cohesiveness peaked at 4% then declined, and springiness improved up to 8% before tapering. Gumminess and chewiness also peaked near 8% powder, suggesting an optimal middle ground where the jelly feels firm yet pliant, not brittle or gummy.
Phytochemical and antioxidant gains were clear: TFC rose from 1.58 to 14.99 mg QE/100 g, TPC from 12.72 to 39.99 mg GAE/100 g, while DPPH and ABTS activities climbed to 90.67 and 51.72 mg VCE/100 g, respectively. Even at 8% powder, the jelly showed substantial antioxidant enhancement, underscoring the potential of fruit-vegetable fortification to boost health benefits without compromising flavor.
Sensory and practical implications
The 30-adult panel largely echoed the instrumental data. Overall liking was lowest at 2% powder and peaked at 8%, with 8% also ranking highest for odor and taste. Texture scores remained broadly stable, but the overall preference trend clearly favored mid-to-higher powder levels. The findings suggest that 8% fruit-vegetable powder provides a sweet-spot: richer color, brighter fruit notes, stronger antioxidants, and a satisfying bite, all while preserving a low-sugar profile and appealing mouthfeel.
Conclusions and industry relevance
The study demonstrates that an erythritol-sweetened collagen jelly can be both low in sugar and high in consumer appeal when fortified with fruit-vegetable powder. Approximately 8% powder emerged as the best compromise, enhancing color, texture, and antioxidant capacity without pushing the gel into an overly firm or adhesive territory. While broader consumer panels and microbial stability studies are needed, the results offer actionable targets for product developers aiming to deliver glucose-friendly, antioxidant-rich snacks that still feel indulgent.
