In the field of food research, new ingredients, compounds, and properties in raw materials are constantly being identified, opening knowledge gaps and generating opportunities for the development of innovative products. At the same time, global dietary habits have evolved, driving a growing demand for healthier, more sustainable alternatives aligned with ethical, environmental, and functional principles. Among the main trends are the preference for plant-based foods, the valorization of traditional crops, and the increasing interest in functional foods—those that offer benefits beyond basic nutritional value. The formulation of plant-based foods can be adapted for consumers with lactose intolerance, individuals following vegan diets, or the general public seeking more sustainable and responsible options, which significantly broadens the scope of functional foods. This research aimed to develop a functional ice cream using optimized germinated quinoa flour, incorporating the emerging probiotic Akkermansia muciniphila. Quinoa was selected for its balanced nutritional profile, the presence of bioactive compounds, and its technological adaptability, following a comparative evaluation with other Andean grains (kiwicha and cañihua). Two Peruvian varieties of different colors were used: Rosa de Huancayo (RH, white grain) and Pasankalla (PK, dark grain). Before germination, disinfection treatments were evaluated on the grain, including combinations of chemical agents, heat, and ultrasound. The combination of hot water (50 °C), hydrogen peroxide (2%), and acetic acid (0.1%) proved to be the most effective, significantly reducing microbial load (in aerobic mesophilic bacteria: 1.29–4.08 Log CFU/g) without affecting germination capacity. Enterobacteria showed greater resistance, especially in PK, but the combined treatment achieved the intended objective. Germination was optimized using a factorial design (24, 48, 72 h × 15, 20, 25 °C), evaluating its effect on nutritional content, bioactive compounds, antinutrients, and techno-functional properties. Improvements were identified in calcium (from 97.1 to 140.1 mg/100 g DW in PK; from 87.5 to 135.2 mg/100 g DW in RH), vitamin C (up to 70.22 µg/g DW in PK; 59.23 µg/g DW in RH), and protein content (from 17.09 % to 18.04 % in PK), as well as a reduction of tannins by up to 63% in RH. Optimal conditions for maximizing polyphenols, vitamin C, and protein content, and reducing tannins, were 25 °C for 24 h in PK, and 22.7 °C for 47.3 h in RH, although in the latter only the first two compounds were optimized. With the optimized germinated quinoa flour, a plant-based ice cream formulation was developed using a D-optimal mixture design. The final formulations—RH (8.86% flour, 14.8% fat, 21.3% sugar) and PK (6.00% flour, 13.0% fat, 23.0% sugar)—achieved physical properties comparable to conventional ice cream in terms of viscosity, hardness, and freezing point. The overrun was lower, representing an area for improvement. Nonetheless, the bioactive compounds derived from germinated quinoa were preserved after processing, highlighting antioxidant activity (110.7 ± 8.39 g Trolox equivalents/g DW) in the quinoa RH ice cream. The product’s functionality was evaluated through in vitro simulated gastrointestinal digestion. The ice cream made with RH flour showed sustained release of phenolic compounds, with high antioxidant activity during the gastric phase (up to 1672.57 µg TE/g DW). Regarding A. muciniphila, high viability was maintained during frozen storage (~10⁸ CFU/g), although a progressive decrease was observed during simulated digestion, reaching 10⁵ CFU/g on day 1 and 10³ CFU/g on day 60. Additionally, the impact of the quinoa-based ice cream formulations on gut microbial activity was evaluated by measuring the production of short-chain fatty acids (SCFAs), ammoniacal nitrogen and lactate during in vitro fecal fermentation. Fecal fermentation revealed that quinoa-based ice cream (QIC), with or without A. muciniphila (Akk), stimulated SCFA production, with butyrate (46.95 mM) predominating in QIC and acetate (33.78 mM) in QIC-Akk, while maintaining safe levels of ammoniacal nitrogen. Lactate dynamics indicated balanced microbial fermentation processes. This study presents an innovative strategy for the development of functional ice cream based on germinated quinoa and emerging probiotics. Despite limitations such as reduced probiotic viability during digestion, the results demonstrate the technological feasibility and nutritional potential of Andean grains in plant-based formulations. These findings contribute to the dialogue on sustainable food innovation and the valorization of traditional crops in the design of functional foods.
| Date of Award | 12 Sept 2025 |
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| Original language | English |
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| Awarding Institution | - Universidade Católica Portuguesa
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| Supervisor | Ana Maria Gomes (Supervisor), Cristina L. M. Silva (Co-Supervisor) & José António Couto Teixeira (Co-Supervisor) |
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