ABSTRACT: This research aimed to assess the influence of red dragon fruit peels ratio (RDF-PR) from two species, Hylocereus hybridum (HH) and Hylocereus undatus (HU), and particle size (PS) on quality parameters of red dragon fruit peel powder (RDF-PP) and its further application in emulsified alpaca-based sausages as partial substitutes of pork-back fat. A three-level full factorial design (nine treatments) was employed to evaluate the effect of RDF-PR (HH(0%):HU(100%), HH(50%):HU(50%), and HH(100%):HU(0%)) and PS (499-297, 296-177, and <177 µm) on the dependent variables: L*, a*, b*, C, h°, water-holding capacity, oil-holding capacity, swelling capacity, pectin yield, degree of esterification (analysed through FT-IR), and crude fibre content. The data analysed through a response surface methodology showed that treatment one (T1) is the best with the optimised conditions at 100% HU RDF-PR and PS of <177 µm. The statistical validation of T1 exhibited the highest water-holding capacity (32.1 g/g peel), oil-holding capacity (2.20 g oil/g peel), and pectin yield (27.1%). A completely randomised design (four formulations) was then used to assess the effect of partial replacement of pork-back fat by T1 in emulsified alpaca-based sausages on the colourimetric, physicochemical, and texture properties (hardness, chewiness, cohesiveness, springiness, adhesiveness, and adhesive force). Likewise, a sensory hedonic scale was employed to evaluate the appearance, colour, odour, flavour, texture, and overall acceptability of sausages. The results revealed that 65.7% of pork-back fat content was successfully replaced compared with a control formulation. Additionally, F3 showed significantly (p < 0.05) better colourimetric, physicochemical, and textural characteristics, such as lower hardness (34.8 N) and chewiness (21.7 N) and higher redness (a* = 19.3) and C (22.9), compared to a control formulation. This research presents RDF-PP as a promising fat substitute for developing healthier, reduced-fat meat products using fibre-rich agroindustry by-products.
