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Jadán Piedra, Felipe
Cereals as sources of lysine in the reformulation of meat products. Evaluation using a biosensor
Effect of Ph on the Physicochemical Properties of a Cassava Peel Starch Biopolymer
2025
,
Erika Alvarez Cañarte
,
Guilber Vergara Velez
,
Frank Guillermo Intriago Flor
,
Efrain Pérez Vega
,
Miguel Andrès Falconi Vèlez
,
Delia Noriega Verdugo
,
Génesis Pamela García García
,
Livis Sharith Díaz Alarcón
,
Andrés Miguel Anchundia Loor
,
Carlos Jadán-Piedra
,
Jadán Piedra, Felipe
The energy and protein requirements of the population must be met, and the use of new analytical methods for rapid, low-cost detection of essential elements like lysine in reformulated foods is crucial. In this context, conditions were evaluated to develop a biosensor with lysine alpha oxidase (LOx), which showed high affinity for lysine with a KM of 0.32 mM. Different concentrations of cereals and legumes (70-30; 55-45; 85-15; quinoa-Lablab Purpureus; pole beans-Lablab Purpureus; and rye-Lablab Purpureus) were incorporated into meat sausages to enrich lysine, achieving a significant increase in lysine concentration (up to 75%) when 15% quinoa was substituted. The potentiometric signal, related to oxygen consumption during lysine oxidation, was detected at 15 s using a voltage of −600 mV. The biosensor, coupled with the immobilized enzyme, allowed the use of low volumes. A positive relationship was found between oxygen consumption (mg O2/L∗s-1) and lysine concentration in the range of 0.01–0.2 mM, with an R2 of 0.9964. The immobilized enzyme-based sensor demonstrated good sensitivity (0.01 mM) and the membrane could be reused up to 18 times, maintaining 92% of its initial activity after 70 days. The biosensor method showed minimal residue formation and had a strong correlation with high-performance liquid chromatography (HPLC) results, validating its accuracy
2025
,
Anchundia, Lisbeth
,
Jadán Piedra, Felipe
,
Macías Alcívar, José
,
Sánchez Mendoza, Virginia
,
Giler Intriago, Sonia
Background/Aims: This study investigates how pH levels affect the characteristics of biopolymer films manufactured from cassava peel starch. Cassava peel starch‘s abundance and biodegradability make it a promising candidate for sustainable packaging. The study seeks to improve film qualities such as thickness, density, moisture content, solubility, and optical properties by altering pH levels. Understanding these effects is critical for increasing the acceptability of cassava peel starch biopolymers in a variety of industrial applications, notably environmentally friendly packaging solutions. Methods: Starch extracted from cassava peel was used to produce films using the casting method at specified pH levels. The films were evaluated for thickness and density using classical methods. Moisture content was determined following the AOAC 930.15 (2000) protocol. Color analysis was conducted using the CIELab color space technique. Water solubility and solubility in acidic (HCl) and alkaline (NaOH) solutions were assessed through chemical solubility tests performed by gravimetry. Results: The study investigated how pH impacts biopolymer films manufactured from cassava peel starch. The film thickness varied greatly across pH levels, with pH 10.5 creating the thickest films (0.158 ± 0.012 mm) and pH 6.5 providing the thinnest (0.118 ± 0.015 mm). Density varied slightly, from 1.393 ± 0.122 g/cc to 1.551 ± 0.153 g/cc. Moisture content fluctuated significantly, affecting biodegradability. Color study indicated pH-dependent variations in transparency and opacity, with higher pH values resulting in larger color deviations (∆E). Water solubility remained constant, but NaOH solubility dropped with increasing pH, peaking at pH 7.5 (23.44 ± 2.82%). Conclusion: This work investigates the use of cassava peel starch for biopolymer synthesis at controlled pH levels. The findings demonstrate the material‘s practicality and provide critical insights for enhancing film qualities, particularly in a variety of industrial applications and environmentally friendly packaging solutions.