David Picha

Dr. David Picha


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 July 2023 in Polish Journal of Food and Nutrition Sciences
Verified
Journal Article
Open access
DTDinh Thi Tran
Dinh Thi Tran
LNLan Thi Hoang Nguyen
Lan Thi Hoang Nguyen
CNCuong Ngoc Nguyen
Cuong Ngoc Nguyen
MHMaarten L. A. T. M. Hertog
Maarten L. A. T. M. Hertog
BNBart Nicolaï
Bart Nicolaï
DPDavid Picha
David Picha
Lycopene, the pigment principally responsible for the red color of tomatoes, is well-known for its strong antioxidant property and substantial health benefits. In this study, the optimal combination of factors for lycopene extraction from tomato pomace was identified using response surface...

19 September 2023 in Fermentation
Verified
Journal Article
Open access
PDF file
RARicardo Jose Aleman
Ricardo Jose Aleman
DADany Avila
Dany Avila
AAAllan Xavier Avila
Allan Xavier Avila
JFJhunior Abrahan Marcía Fuentes
Jhunior Abrahan Marcía Fuentes
DPDavid Picha
David Picha
IFIsmael Montero Fernández
Ismael Montero Fernández
Weevil (Rhynchophorus palmarum) powder, teosinte (Dioon mejiae) and Caesar’s mushroom (Amanita caesarea) flour have bioactive compounds with significant nutritional applications. This paper aimed to examine the influence of weevil, teosinte, and mushroom powders on the protease activity, acid tolerance, bile tolerance, lysozyme tolerance, and gastric juice resistance ability of Lactobacillus acidophilus LA-K. Acid tolerance was determined by adjusting the pH of MRS broth to 2.0 for L. acidophilus incubated under aerobic conditions at 37 °C. Bile tolerance was determined by incorporating 0.3% of oxgall. Protease activity was determined spectrophotometrically at 340 nm. Resistance to 100 mg/L of lysozyme in an electrolyte solution was also determined. All ingredients were incorporated at 2% (w/v), while the control had no added ingredients. Acid and lysozyme tolerance were examined at 0, 30, 60, 90, and 120 min of incubation, whereas bile tolerance was analyzed at 0, 4, and 8 h. Gastric juice tolerance was determined at pH 2, 3, 4, 5, and 7 during 0 and 30 min of incubation, while protease activity was evaluated at 0, 12, and 24 h. Use of weevil flour, and Caesar’s mushroom powder resulted in significantly (p < 0.05) lower counts for bile tolerance, acid tolerance, lysozyme resistance and simulated gastric juice tolerance characteristics. Protease activity increased with the use of teosinte flour. As such, this probiotic bacterium can be used alongside certain novel food sources at 2% concentration in the manufacture of fermented products such as yogurt.

28 July 2023 in Fermentation
Verified
Journal Article
Open access
PDF file
RARicardo Jose Aleman
Ricardo Jose Aleman
DADany Avila
Dany Avila
AAAllan Xavier Avila
Allan Xavier Avila
JLJack Losso
Jack Losso
DPDavid Picha
David Picha
KAKayanush Aryana
Kayanush Aryana
Nipple fruit (Solanum mammosum) has been considered to have great pharmaceutical potential because of its high amounts of solamargine and solasonine. This study aimed to examine the effect of nipple fruit at different concentrations (0.5%, 1%, and 2% (w/v)) on the viability, acid, bile, lysozyme, and gastric juice tolerance, and protease activity of Lactobacillus acidophilus LA K. The viability was studied in MRS broth. Acid tolerance was determined by adjusting the pH to 2, whereas bile tolerance was examined with oxgall 0.3% (w/v) in MRS broth. Lysozyme resistance was investigated in an electrolyte solution with lysozyme (100 mg/L), while gastric juice tolerance was analyzed with pepsin and NaCl. Protease activity was determined spectrophotometrically at 340 nm in skim milk with o-phthaldialdehyde reagent. L. acidophilus LA K was incubated anaerobically (37 °C). Microbial growth was determined every 2 h for 10 h of incubation. Acid tolerance was determined at 0, 5, and 15 min, whereas bile tolerance was analyzed at 0, 4, and 8 h of incubation. Lysozyme tolerance was determined at 0, 1, and 2 h of incubation, while gastric juice tolerance was determined at pH 2, 3, 4, 5, and 7. Protease activity was evaluated at 0, 12, and 24 h incubation. Nipple fruit’s chemical and bioactive compounds were also examined to discuss their impact on the survival of L. acidophilus LA K. Nipple fruit did not affect microbial growth, bile, and acid tolerance. Nipple fruit at 2% had higher survivability on the simulated gastric juice and lysozyme resistance and increased protease activity.

30 March 2024 in Bacteria
Verified
Journal Article
Open access
PDF file
Migue Mariano TaboraMigue Mariano Tabora
Migue Mariano Tabora
RARicardo Jose Aleman
Ricardo Jose Aleman
ACAshly Yoselin Castro
Ashly Yoselin Castro
AAAllan Xavier Avila
Allan Xavier Avila
DADany Avila
Dany Avila
KAKayanush Aryana
Kayanush Aryana
Carao (Cassia grandis) contains numerous bioactive substances that contribute to gastrointestinal well-being. The present study assessed the potential impacts of carao on the viability and performance of Streptococcus thermophilus and Lactobacillus bulgaricus under various adverse conditions. These conditions included bile, acid, gastric juice, and lysozyme exposure, simulating the digestive process from the mouth to the intestines. The activity of proteases from cultures was monitored to examine their proteolytic capabilities. To achieve this, the cultures were cultivated in a solution containing plant material, and the results were compared against a control sample after an incubation period. Subsequently, the total phenolic content, total carotenoid content, antioxidant activity, sugar profile, and acid profile of the plant materials were analyzed. These analyses were conducted to explore these compounds’ influence on cultures’ survival. Seeds contained the highest total phenols (766.87 ± 11.56 µg GAE/mL), total carotenoid content (7.43 ± 0.31 mg Q/mL), and antioxidant activity (40.76 ± 1.87%). Pulp contained the highest moisture (12.55 ± 0.44%), ash (6.45 ± 0.15%), lipid (0.66 ± 0.07%), protein (16.56 ± 0.21%), sucrose (9.07 ± 0.78 g/100 g), and fructose (3.76 ± 0.06 g/ 100 g). The crust had the highest content of ash (85.14 ± 0.27%) and succinic acid (2.01 ± 0.06 g/100 g). Results indicated that seeds negatively affected cultures’ survival in the bile tolerance test and had positive effects on Lactobacillus bulgaricus in the protease activity test. Otherwise, the other carao tissues could not change the results significantly (p > 0.05) compared to the control in different tests. The carao crust positively affected cultures’ against protease activity, especially in Lactobacillus bulgaricus, and had a negative effect on the growth of S. thermophilus in the lysozyme and gastric acid resistance test.