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This study reports on aflatoxin production and peanut (Bailey's variety) quality, for four peanut pre-storage treatments; [(Raw clean (Raw-Cl), Raw inoculated with NRRL 3357 (Raw-Inf), inoculated partially roasted but not-blanched (PRN-blanch); and inoculated partially roasted, blanched with discolored nuts sorted out (PR-blanched)]. All four treated samples were packaged in four different packaging systems [polypropylene woven sacks (PS), hermetic packs (HP), hermetic packs with oxygen absorbers (HPO), and vacuumed hermetic packs (HPV)] and stored under controlled conditions at a temperature of 30 ± 1 °C and water activity of 0.85 ± 0.02, for 14 weeks. Raw-Inf samples in PS had a higher fungal growth with a mean value of 8.01 × 10 CFU/g, compared to the mean values of samples in hermetic packs: 1.07 × 10 CFU/g for HP, 14.55 CFU/g for HPO, and 57.82 CFU/g for HPV. Similarly, the hermetic bags were able to reduce aflatoxin level of the Raw-Inf samples by 50.6% (HP), 63.0% (HPV), and 66.8% (HPO). Partial roasting and blanching in PS also reduced aflatoxin level by about 74.6%. Quality maintenance was the best for peanuts in HPO, recording peroxide value (PV) of 10.16 meq/kg and -Anisidine (-Av) of 3.95 meq/kg compared to samples in polypropylene woven sacks which had PV of 19.25 meq/kg and -Av of 6.48 meq/kg. These results indicate that using zero-oxygen hermetic packaging, instead of the conventional polypropylene woven sacks, helped to suppress aflatoxin production and quality deterioration. Also, partially roasted, blanched and sorted peanuts showed a potential for reducing aflatoxin presence during storage.

Aspergillus colonization on peanuts is a growing concern, as it results in reduced crop yields or livestock productivity due to consumption of contaminated feed, and most importantly, they are famous as causative agents of opportunistic infestation in man. In order to defeat and evaluate peanuts suffering from Aspergillus infection, it is essential to establish proper technique and track the quality of peanuts at both farm and market levels. This study focuses on usage of Fourier transform mid-infrared spectroscopy (FTIR) with a non-invasive reflectance apparatus, photoacoustic spectroscopy (PAS) to identify and separate infected peanuts based on spectral characteristics of infrared radiation on peanuts. Classes were defined as Bclean^representing no-aflatoxin/nomold in peanuts, Bmoldy^representing peanuts with nonaflatoxigenic Aspergillus strains, and lastly, Btoxicr epresenting peanuts infected with aflatoxigenic strains of Aspergillus spp. Classes were analyzed using discriminant analysis algorithm, and distance values were calculated in Mahalanobis distance units. The spectral ranges between 3600 and 2750, 1800 and 1480, and 1200 and 900 cm −1 were assigned as the key bands, and corresponding vibration modes and intensities were labeled. All healthy, clean peanuts (15 healthy/69 total peanut pods) were successfully separated from moldy ones. Separation was further detailed to distinguish peanuts infected with aflatoxin producing strains of Aspergillus flavus and Aspergillus parasiticus, and as a result, 87 % of samples were separated correctly as only moldy or toxic streams. Performance test was conducted with 36 different samples including toxic, moldy, and clean samples; 80.6 % correct classification was achieved.