Abstract We studied the effect of the calyx of cape gooseberry nanoparticles manufactured by a novel technique. There are several methods, such as jet mill, spray freezing, supercritical anti-solvent technique (SAS), and high-pressure homogenization, available for the production of drug micro/nanoparticles to improve drug solubility. Anti-solvent precipitation is also used to prepare micro- and nanosized particles to explain their effects on different foodborne pathogens, contaminated bacteria, and some fungi. Results indicated that nanoparticles of the cape gooseberry calyx contained higher antioxidant activity than that found in the normal calyx, seed, and juice. While studying the effect of cape gooseberry calyx nanoparticles on microorganisms, it was found that the zone of inhibition was highly positive against Bacillus cereus, B. subtilis, Staphylococcus aureus, Clostridium perfringens, and Salmonella typhimurium compared to that of the normal cape gooseberry calyx. All species of molds, including Mucor sp., Aspergillus niger, Penicillium sp., and Alternaria sp., and yeasts like Saccharomyces cerevisiae and Rhodotorula glutinis were affected by nanoparticles of the cape gooseberry calyx compared to those of the normal calyx.

Abstract A novel method to create nanoparticles from freeze- and air-dried mangosteen was developed to study the effects of these particles on the growth and protein formation of various gram-positive bacteria that act as foodborne pathogens. This new method produces freeze- and air-dried mangosteen peel nanoparticles that are prepared by a process based on a wet-milling technique, and these particles were tested on various gram-positive pathogenic bacteria. Our results indicated that the nanoparticles derived from freeze dried mangosteen contained higher antioxidant activity than nanoparticles derived from air-dried peels. The total phenol content in the freeze-dried nanoparticle extract was 1112.646 ± 1.842 (mg gallic acid /g sample), whereas that in the air-dried extract was 479.744 ± 2.564 (mg gallic acid/g sample). The total flavonoids in the mangosteen freeze-dried nanoparticle extract were 14.154 ± 0.119 (mg catechin/g sample), whereas levels in the air-dried extract were 4.711 ± 0.207 (mg catechin/g sample). The levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) were 95.707 ± 0.070 and 94.303 ± 0.074% for freeze- and air-dried mangosteen nanoparticle extracts, respectively. Similar levels were obtained for 2,4,6-tri (2-pyridyl)-s-triazine (ABTS), and these were 42.753 ± 0.200 and 16.069 ± 0.424 (g trolox/g sample) for freeze- and air-dried mangosteen nanoparticle extracts, respectively. Levels of ferric reducing antioxidant power (FRAP) were 17.806 ± 0.056 and 6.696 ± 0.085 (g trolox/g sample) for freeze- and air-dried mangosteen nanoparticle extracts, respectively. Whole protein bands from various bacteria disappeared on SDS-polyacrylamide gels when bacteria were cultured in medium containing both freeze- and air-dried mangosteen nanoparticles.

Abstract Seventy eight yeasts were isolated from different foodstuffs. Out of the seventy eight isolates four yeast species namely C. parapsilosis Q3, C. solani F8, C. versatilis J3 and K. jensenii H1 were selected to study their biological activity. The four strains termed as killer yeast by observing its activity against microorganisms. Killer yeasts secrete proteinaceous killer toxins lethal effect against some of Gram positive and negative bacteria, molds and yeasts. The antagonistic effect of the four killer yeast strains on the growth of different microorganisms recorded as zone of inhibition (mm), demonstrated that C. versatilis J3 was an active stains against majority test microorganisms. Consumed sugar determined for the four strains and showed that C. versatilis J3 and C. parapsilosis Q3 reached to its maximum on the 12 hours of incubation both yeast consumed 97.5 and 95% of initial sugar (sugar utilization efficiency) while both of C. solani F8 and K. jensenii H1 sugar utilization efficiency was recorded on the 24 hours being 99.65 and 99.30%, respectively.

Abstract Citrox has natural antibacterial effect against many foodborne pathogens and contaminated bacteria. It mainly contains citric acid, ascorbic acid, and malic acid. We studied the antimicrobial effects of citrox solution (1% and 2%) on the total viable count of methicillin-resistant Staphylococcus aureus (MRSA) on chicken meat fillet. The samples were treated with 106 CFU/g of meat, vacuum-packed (VP), and 4 °C for 3, 6, 9, 12, 15, 18, 21 days. We have also studied the effect of citrox on the total volatile basic nitrogen (TVBN) content and pH changes during the storage periods. The results revealed that citrox inhibited the growth of methicillin-resistant S. aureus (MRSA), in the chicken fillet. The total viable count of MRSA gradually decreased in all treated samples that were stored at 4 °C about 2 log cycle than Chicken-Staph groups after 3, 6, 9, and 12 days and about 1 log cycle than Chicken-Salt group after 3, 6, and 9 days of storage. Total volatile base nitrogen (TVB-N) were observed to be reduced in Chicken- Citrox-treated samples stored at 4 °C than Chicken-Staph, and Chicken-Salt treated samples. The results indicated that citrox is effective to reduce the total count of S. aureus (MRSA) in the first three days of storage by a reduction in the number of bacteria 1 log cycle.