Quality of beans (Phaseolus vulgaris L.) after postharvest microwave treatments

ABSTRACT

The potential of microwave heating (2450 MHz) was studied as a postharvest treatment on the quality of beans (Phaseolus vulgaris L.). Two of the most consumed bean varieties in Mexico were considered: ‘Bayo’ and ‘Negro’, with 11.3% and 10.7% (w.b.) of moisture content, respectively. Different power levels – 370, 510 and 950 W – were evaluated. The different treatment times were determined as the time needed to reach 48.9 °C at the centre of the beans, this target temperature is recommended to control bean weevil. Then, the beans were cooled with air flowing at 2.8 m/s at a temperature of 24 °C (60% RH). Several quality parameters were evaluated after treatment (moisture content, water activity, germination ability, hardness and cooking time). Cooking time was well modelled by Fermi equation. The treatment that showed the best results was 370 W for 72 s in ‘Bayo’ variety and 54 s in ‘Negro’ variety.

KEYWORDS:

• Beans
• microwave treatment
• disinfestation
• germination
• cooking time

Acknowledgments

Authors thank the financial support from CONACyT (Consejo Nacional de Ciencia y Tecnología, Mexico) for M. Aguilar-Morales and for Project 168990. Also, thanks to Dr Rossana Villa-Rojas, for her valuable suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

CONACyT (Consejo Nacional de Ciencia y Tecnología, Mexico) [project number 168990.]

Notes on contributors

María Elena Sosa-Morales

María Elena Sosa-Morales is a Professor of New Product Development and Food Technology of the Department of Food Engineering at División de Ciencias de la Vida, Campus Irapuato-Salamanca of Universidad de Guanajuato, Mexico. Her current research interests include microwave and radiofrequency with application in foods, as well as frying.

Mariana Aguilar-Morales

Mariana Aguilar-Morales is a youth Food Engineer. She studied the undergrad program at Universidad de las Américas Puebla, Mexico, and now is devoted to food industry.

Abel Cerón-García

Abel Cerón-García is a Professor of the Department of Food Engineering at División de Ciencias de la Vida, Campus Irapuato-Salamanca of Universidad de Guanajuato, Mexico. His research is focused on bio compounds and enzymes from vegetal foods and their byproducts.

Roberto Rojas-Laguna

Roberto Rojas-Laguna is a Professor of Calculus, Electromagnetic Theory and Optical Fiber Applications of the Department of Electronics at División de Ingenierías, Campus Irapuato-Salamanca of Universidad de Guanajuato, Mexico. He is conducting projects on optical fiber sensors and simulation of non-linear phenomena in optical fibers.

Aurelio López-Malo

Aurelio Lopez-Malo is a Professor of Food Microbiology of the Department of Chemical, Environmental and Food Engineering at Universidad de las Américas Puebla, Mexico. He is a leader of diverse scientific projects in natural antimicrobial agents and for food industry. His current interests focus on predictive microbiology, essential oils applications and engineering education.