Cinnamon essential oils (CEOs) from leaf and bark were investigated for their antimicrobial potential against Salmonella typhimurium and Listeria monocytogenes. Minimum inhibitory concentration of leaf and bark CEOs against S. typhimurium and L. monocytogenes at low (4-log CFU/ml) and high (9-log CFU/ml) initial concentrations was 0.5% (vol/vol). When applied on fresh celery previously inoculated with S. typhimurium or L. monocytogenes, 0.5% leaf and bark CEOs significantly reduced (p < 0.05) the growth of S. typhimurium and L. monocytogenes. Leaf and bark CEOs could give a better log reduction against L. monocytogenes inoculated at low and high initial bacterial concentrations (2.1 logs and 4.0-4.1 logs, respectively) on the celery as compared to S. typhimurium (1.8-2.0 logs and 2.8-3.2 logs in reduction, respectively), after 7 days of storage at 4 degrees C. Hence, leaf and bark CEOs can be potential antimicrobial agents to keep fresh produce safe from Salmonella and Listeria for human consumption. Practical applications This study showed that essential oils (CEOs) from cinnamon bark and leaf could be applied as natural antimicrobials to prevent contaminations of foodborne bacteria, such as Salmonella typhimurium and Listeria monocytogenes in fresh and pre-cut produce. The minimum inhibitory concentration of these essential oils against these pathogens was 0.5% vol/vol. Bark and leaf CEOs could be a potential antimicrobial agent to keep fresh produce safe from foodborne pathogens.

The effect of organic acid electrostatic spraying on Salmonella Typhimurium inoculated fresh produces and their texture and color changes was evaluated. Inoculated cantaloupe cubes and cherry tomatoes were electrostatically sprayed with varying concentrations of malic and lactic acids and monitored over 11-day storage at 4 degrees C. Malic acid (4%) could significantly reduce Salmonella growth on cantaloupe cubes up to 2.6-log CFU/g by electrostatic spraying and only 0.9-log CFU/g by conventional spraying (p < 0.05). However, there was no significant difference (p > 0.05) using both methods in the log numbers of Salmonella survived on cherry tomatoes over 11-day storage. The electrostatic spraying treatments did not cause much effect on the color and texture of the produce samples. These findings suggest that the safety of fresh and fresh-cut produce may be enhanced using malic acid or combined with lactic acid applied by an electrostatic spraying system. Practical applications The current study illustrates the importance of natural antimicrobial organic acids that can minimize pathogenic Salmonella contaminations on fruits and vegetables. Electrostatic spray method reduces loss of treatment solutions while enhancing their antimicrobial activity without affecting their texture and color. This can lead to commercialization of the technology which can protect consumers from food-borne illnesses due to contaminations.

Cinnamon leaf and bark essential oils have long been used as natural preservatives and flavoring agents in foods. This study determined antimicrobial effects of leaf and bark of cinnamon essential oils (CEOs) against 2 foodborne pathogens, Salmonella Typhimurium (S.T.) and Listeria monocytogenes (L.m.), at 2 initial bacterial levels (4- and 9-log CFU/mL) in strawberry shakes. The antimicrobial study of CEOs at 0.1% and 0.5% in strawberry shakes against S.T. and L.M. showed a significant difference (P < 0.05) in log reductions of both bacterial growth at low (4-log CFU/mL) and high (9-log CFU/mL) initial bacterial levels. Addition of 0.5% CEOs into strawberry shakes at 4 °C completely inhibited both bacteria after a period of 8 d storage. Shelf-life study showed that acidity and total solid content were not affected during storage. The strawberry shakes containing bark CEO had higher ratings of sensory acceptability compared to leaf CEO, with or without the addition of 1% masking agent. In conclusion, this study demonstrated that CEO derived from bark was better than that from leaf in terms of their antimicrobial activity and sensory aspect.PRACTICAL APPLICATION:This study demonstrates that essential oils derived from cinnamon bark and leaf have the potential to be used as natural antimicrobial ingredient in milk beverages with respect to sensory aspect. This finding promotes the acceptance of natural antimicrobials among consumers, while providing enhanced safer products to the food industry application.

A peptide from protein hydrolysate fraction obtained from a high oleic acid soybean line (N98-4445A) that had shown significant activity against human cancer cell lines was identified and purified. Three peptides showing highest activity were identified by reverse phase HPLC in the 10–50 kDa fraction of the protein and purified using peptide specific affinity chromatography column. The three individual peptides were tested for anti-proliferative activity against blood, colon and liver cancer cell lines using 3-(4,5-dimethyl thiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell titer assay. Enhanced colon cancer cell inhibition (80%) was observed after testing a pure peptide (molecular size of 18 kDa with 158 amino acid residues) which also demonstrated a time-response of 96 hr after incubation based on trypan blue dye exclusion study. The impact of this study lies in deriving a pure single peptide with anti-proliferative activity on human colon and blood cancer cells. Practical applications Soybean is cultivated in the United States mostly for extracting the oil leaving the residue (soybean meal) which is commonly used as an animal feed due to its high protein content. This study has shown that soy peptides produced enzymatically from the meal of a high oleic acid soybean line (N98-4445A) were found to have anticancer activity. This study demonstrated an impending value for a pure peptide derived from this soy peptides as an alternative and inexpensive anti-cancer therapeutic agent as well as a value addition to soy meal by-product.

In this study, we examined in vitro the bio-activity of peptide fractions obtained from soybeans against blood (CCRF-CEM and Kasumi-3), breast (MCF-7), and prostate (PC-3) cancer cell proliferation. Gastro-intestinal treated peptide fractions (<5, 5–10 and 10–50 kDa) prepared from seed proteins of two high oleic acid soybean lines—N98-4445A, S03-543CR and one high protein line—R95-1705, were tested for anticancer activity against human breast, blood and prostate cancer cell lines. Anti-proliferative cell titer assay was conducted to assess the inhibitory effects of the peptide fractions, while trypan blue dye exclusion assay was used to determine the dose response of most effective fractions. Results showed that the peptide fractions inhibited the cancer cell lines up to 68.0% and the minimum concentration to get 50% inhibitory activity (IC50) ranged between 608 and 678 µg/mL. This multiple site in vitro cancer inhibition by GI friendly peptides could have the potential use as food ingredients or nutritional supplements in an alternative cancer therapy.

Soybean hulls or seed coats consist of complex carbohydrates, proteins, lipids, and polyphenols such as anthocyanidins, proanthocyanidins, and isoflavones. The polyphenolics in the seed coats give them various colors such as black, brown, green, yellow, or even a mottled appearance. In this study, the antimicrobial effects of phenolic extracts from the seed coats of different colored soybeans (yellow, dark brown, brown, and black) were evaluated against foodborne pathogens such as Salmonella Typhimurium, Escherichia coli O157:H7, and Campylobacter jejuni in broth-cultures as well as on chicken skin. The highest total phenolic content was observed for the phenolic extract from soybean variety (R07-1927) with black colored seed coat (74.1 ± 2.1 mg chlorogenic acid equivalent [CAE]/g extract) and was significantly different (P <0.0001) from the extract of the conventional soybean variety (R08-4004) with yellow colored seed coat (7.4 ± 1.2 mg CAE/g extract). The extract from black colored soybean produced reductions of 2.10 ± 0.08 to 2.20 ± 0.08-log CFU/mL for both E. coli O157:H7 and C. jejuni after 3 d when incubated in broth-culture having 4-log CFU/mL of bacteria, whereas a 6 d incubation was found to reduce S. Typhimurium and E. coli O157:H7 at 2.03 ± 0.05 and 3.3 ± 0.08-log CFU/mL, respectively. The extract also reduced S. Typhimurium and E. coli O157:H7 attached to chicken skin by 1.39 ± 0.03 and 1.24 ± 0.06-log CFU/g, respectively, upon incubation for 6 d. Soybean seed coat extracts may have a potency as antimicrobial agents to reduce foodborne bacteria contaminating poultry products.

Campylobacter jejuni is one of the leading causes of human gastroenteritis. Campylobacter jejuni requires special conditions and media in the laboratory for its growth. In nature, however, this organism is able to survive in very diverse and hostile environments and produce disease in humans and animals. The different mechanisms by which C. jejuni survives stressful conditions in the environment still remain unclear. Stress-adaptation may be one of the factors helping this organism to survive stresses. Some C. jejuni strains have been found to have increased antibiotic resistance in last several years. To determine the effect of acid adaptation on the antibiotic sensitivity profile of C. jejuni, 4 different isolates of C. jejuni (a human isolate and 3 poultry isolates) were exposed to an acid pH of 5.5 and then rechallenged with different stresses. The antibiotic sensitivity profiles of C. jejuni after stress-adaptation were compared with antibiotic sensitivity profiles of non-stressed C. jejuni using the Kirby Bauer agar disc diffusion assay. The antibiotic sensitivity profiles of the C. jejuni isolates used in this study were found to change when the acidadapted bacteria were subjected to further stresses such as an acidic pH of 4.5, aerobic atmosphere and starvation. In the majority of the cases, antibiotic-resistant C. jejuni isolates were found to be more sensitive to antibiotics after stress-adaptation, but in a few cases C. jejuni showed increased resistance. These results indicate that increasing various stresses in a sequential pattern may, in some cases, reduce antibiotic resistance of C. jejuni isolates.

The aim of this study was to determine the influence of acid-adaptation on the survival as well as adhesion and invasion of human intestinal cells by nine Campylobacter jejuni strains after exposure to different stress conditions. Acid-adapted and nonadapted C. jejuni were exposed to different secondary stress conditions such as acid (pH 4.5), starvation (phosphate-buffered saline, pH 7.2), or salt (3% wt/vol NaCl). After exposure to the secondary stress, the adhesion and invasion abilities of the strains were evaluated in vitro in tissue culture using the human intestinal cell line INT 407. The survival rates of acid-adapted cells of some strains of C. jejuni exposed to different secondary stresses were found to be significantly higher than the non-acid-adapted cells. Similarly, some strains also showed an increase in adhesion and invasion (p<0.05) when acid-adapted C. jejuni were exposed to stresses such as acid, starvation, or salt as compared to non-acid-adapted C. jejuni. We found that adaptation to acid stress can enhance the survival of C. jejuni when exposed to secondary stresses and, thus, result in increased adhesion and invasion of human intestinal cells in vitro. However, the survival rates as well as the degree of adhesion and invasion were found to vary with the strain of C. jejuni, the time of adaptation to acid, the type of the secondary stress and exposure time to the secondary stress. These results show that adaptation to stresses could influence virulence of C. jejuni. Understanding the conditions by which C. jejuni adapts to stresses will provide information concerning how this organism is able to survive inside and outside the host. This, in turn, could offer methods to reduce or eliminate C. jejuni in the environment.