Decontamination of Bacillus cereus in cardamom ( Elettaria cardamomum ) seeds by infrared radiation and modeling of microbial inactivation through experimental models

Continuous decontamination of cumin seed by non-contact induction heating technology: Assessment of microbial load and quality changes

Over the past few decades, the demand for high-quality food has increased steadily. Therefore, it is essential to develop innovative technologies that effectively reduce microbial load while minimizing any negative effect on the quality of spices. The objective of this study was to determine the efficacy of a self-designed non-contact induction heating system using contaminated cumin seeds. The non-contact induction heating decontamination process was performed at different temperatures of 115, 135 and 155°C and durations (45, 60 and 75 s) through continuous process (screw conveyor) in Pyrex cylinder chamber. Various parameters including microbial load, color characteristics, essential oil content, surface morphology, sample temperature, and energy consumption were analyzed as dependent variables in the study. The results showed that the treatment combination (155°C - 60 s) reduced the aerobic plate count from 6.21 to 2.97 CFU/g. Mold, yeast and coliforms in the treatment combination (155°C-45 s) were also reduced by 3.26 and 3.6 CFU/g, respectively. The total color difference of the samples increased due to the degradation and alteration of pigments at high temperatures. However, no statistically significant disparity in essential oil content was observed between the treatment groups and the control group. The quantities of essential oil components in the cumin seeds were determined to align with the ISO standard, with the primary constituents identified as follows: Terpinen-7-al γ (38.98%), Cumin aldehyde (20.75%), γ-Terpinene (18.81%), β-Pinene (13.66%), and p-Cymene (6.2%). In summary, non-contact induction heating system shows promise as an effective technology for surface decontamination of spices. The acquired findings contribute to a deeper understanding of the impact of the induction heating process on both the microbial contamination levels and the quality attributes of cumin seeds. This scientific knowledge serves as a foundational framework for the prospective adoption and integration of this technology on a larger industrial scale.

Recent developments in applications of physical fields for microbial decontamination and enhancing nutritional properties of germinated edible seeds and sprouts: a review

Germinated edible seeds and sprouts have attracted consumers because of their nutritional values and health benefits. To ensure the microbial safety of the seed and sprout, emerging processing methods involving physical fields (PFs), having the characteristics of high efficiency and environmental safety, are increasingly proposed as effective decontamination processing technologies. This review summarizes recent progress on the application of PFs to germinating edible seeds, including their impact on microbial decontamination and nutritional quality and the associated influencing mechanisms in germination. The effectiveness, application scope, and limitation of the various physical techniques, including ultrasound, microwave, radio frequency, infrared heating, irradiation, pulsed light, plasma, and high-pressure processing, are symmetrically reviewed. Good application potential for improving seed germination and sprout growth is also described for promoting the accumulation of bioactive compounds in sprouts, and subsequently enhancing the antioxidant capacity under favorable PFs processing conditions. Moreover, the challenges and future directions of PFs in the application to germinated edible seeds are finally proposed. This review also attempts to provide an in-depth understanding of the effects of PFs on microbial safety and changes in nutritional properties of germinating edible seeds and a theoretical reference for the future development of PFs in processing safe sprouted seeds.

Novel infrared puffing: Effect on physicochemical attributes of puffed rice ( Oryza sativa L.)

The effect of novel infrared (IR) puffing and various IR powers (350, 450, and 550 Watts [W]) at various distances (10, 20, and 30 cm) on physicochemical characteristics of puffed rice (puffing properties, color, total phenolic content [TPC], antioxidant activity, peroxide value, and morphology) was investigated. By reducing the distance and increasing the IR power, the volume puffing was significantly increased (p < .05), and bulk density was significantly decreased (p < .05) but there was no significant difference in the length/breadth ratio. The IR puffing effect on color, the TPC, antioxidant activity, and food compounds' analysis through Fourier transform infrared (FTIR) spectra were significant (p < .05) during IR puffing. The scanning electron microscopy (SEM) images showed that by increasing the IR power and decreasing the sample distance from the IR source, the size of protrusions was increased (the volume of the protrusions). The maximum increase in the protrusions size was observed in 10 cm distance and 550 W power of IR. This is the first report on the IR puffing of rice and according to the results, the IR puffing technology has a high efficiency at the rice puffing.

Novel pulsed infrared radiation: Effect on microbial, chemical, and sensory properties of saffron (Crocus sativus L.)

AIM

In this study, the effect of pulsed infrared (PIR) irradiation on saffron microbial, chemical, and sensory properties were evaluated.

METHODS AND RESULTS

The PIR power (250, 350, and 450W), the distance of sample with irradiation source (10, 20, and 30cm), irradiation time (0-20min), and PIR pulse (1, 2, and 3pulse/s) were investigated. Decontamination of total bacteria and total mold and yeast flora and microbial inactivation kinetics were determined. Saffron quality by FTIR and HPLC and sensory attributes were also measured. The highest reduction of the total bacterial count (2.203 Log₁₀ CFU/g) and total mold and yeast counts (2.194 Log₁₀ CFU/g) were obtained in Sargol Negin saffron at 350 W PIR power, 10 cm distance, 1.5 min treatment time, and 3 pulse/s. The Double Weibull model is the best-fit model for the prediction of the microbial population.

CONCLUSION

Until now, there have been no reports of application for PIR in food processing and decontamination. According to the results, it can be concluded that PIR can be used as a safe method of saffron processing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Utilization of a proper decontamination method for spices especially saffron as the most expensive agricultural product is challengeable. It is recommended to use the PIR method for food processing because due to the reduction of microbial population, it can maintain foodstuff quality at an acceptable level.

Ultrasound, infrared and its assisted technology, a promising tool in physical food processing: A review of recent developments

Traditional food processing techniques can no longer meet the ever increasing demand for high quality food across the globe due to its low process efficiency, high energy consumption and low product yield. This review article is focused on the mechanism and application of Infrared (IR) and ultrasound (US) technologies in physical processing of food. We herein present the individual use of IR and US (both mono-frequency and multi-frequency levels) as well as IR and US supported with other thermal and non-thermal technologies to improve their food processing performance. IR and US are recent thermal and non-thermal technologies which have now been successfully used in food industries to solve the demerits of conventional processing technologies. These environmentally-friendly technologies are characterized by low energy consumption, reduced processing time, high mass-transfer rates, better nutrient retention, better product quality, less mechanical damage and improved shelf life. This work could be, with no doubt, useful to the scientific world and food industries by providing insights on recent advances in the use of US and IR technology, which can be applied to improve food processing technologies for better quality and safer products.