Soybean peptide fractions inhibit human blood, breast and prostate cancer cell proliferation.

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.

Protein-rich beverage developed using non-GM soybean (R08-4004) and evaluated for sensory acceptance and shelf-life.

Protein beverages have been in demand due to an increasing consumers' interest in healthy eating habit. However, there is an increased concern on the use of genetic modified (GM) ingredient in the food product. This study aimed to develop protein hydrolysate beverages using a non-GM soybean (R08-4004/high protein line) grown in Arkansas. Protein isolate was prepared from the soybean using alkaline method (pH 9.5). Due to its poor solubility in acidic condition, alcalase 2.4 L (food grade protease) hydrolyzed soy protein was used to develop a beverage containing 20 g protein per serving (500 mL). Three flavored beverages: Chai tea (C), tangerine (T), and mixed berries (MB) were prepared using bitter blocker, masking agent, and citric acid to minimize an unpleasant bitter taste developed in the soy hydrolysates. Protein solubility, pH, microbial growth, instrumental color parameters, and turbidity were measured to evaluate the shelf-life stability of the beverages at refrigerated storage (5 °C) for 42 days. Beverages T and MB received overall highest scores from the sensory panel. Citric acid alone or in combination with bitter blocker or masking agent lowered the bitterness. Pasteurization (90-95 °C for 5 min) was effective in preventing microbial growth. Although pH remained constant, decrease in protein solubility and color changes were observed over the storage time in all the three flavored beverages. Cloudiness in beverage C increased over the storage period while beverages T and MB were very stable. Overall, T and MB flavored beverages have the potential for commercial application.

Improved functional properties of glycosylated soy protein isolate using D-glucose and xanthan gum.

Functional properties of the soy protein need to improve to have better applications in food industry. Alkali extracted and acid precipitated soy protein isolate (SPI) was glycosylated using D-glucose (G) and Xanthan gum (X) via Maillard reaction to improve solubility. The effects of SPI to G and SPI to X ratios (SPI:G = 2:1, 1:1, and 1:2; SPI:X = 100:1 and 10:1) and incubation time (0, 6, 12, and 24 h) on the solubility and functional properties of glycosylated SPI were evaluated. The SPI:G ratio of 1:2 yielded a maximum degree of glycosylation of 71.1 %. The solubility of SPI after glycosylation significantly increased (P < 0.05) at pH 4.0-8.0 compared to SPI alone. Although the emulsion stability of glycosylated SPIs has not significantly increased (P > 0.05), the emulsifying activity improved significantly (P < 0.05). Glycosylation with SPI-X at a ratio of 10: 1 showed maximum emulsifying activity of 191.6 m(2)/g (SPI alone: 66.3 m(2)/g). Moreover, the SPI:X (ratio of 100:1) showed the maximum foaming activity (205 mL) compared to SPI alone (155 mL). The foaming stability of SPI (2.6 %) increased to 5.5 and 8.2 % when using xanthan gum at the ratio of 100:1 and 10:1, respectively. Glycosylated SPI with enhanced emulsifying and foaming properties has potential to improve the functional quality of the food products.

Bioactivity of a Rice Bran-Derived Peptide and its Sensory Evaluation and Storage Stability in Orange Juice.

A pentapeptide prepared from rice bran demonstrated growth inhibition on human lung, liver, breast, and colon cancer cell lines. The objectives of this study were to evaluate the human prostate cancer growth inhibition by the pentapeptide and its 6-mo storage stability by incorporating spray-dried orange juice, and determining sensory acceptability. The pentapeptide showed inhibition of human prostate cancer cells by 45% at 460 µg/mL concentration. When incorporated in spray-dried orange juice, and reconstituted with water and tested, there was an approximately 10% degradation of the peptide at 620 µg/mL concentration under refrigerated conditions over a 6 mo storage period, whereas at ambient temperature the degradation was 30%. Larger degradation was observed when 240 or 460 µg/mL pentapeptide was used. Overall, consumer panelists liked sensory aspect of the reconstituted pentapeptide incorporated orange juice beverage. Also consumer panelists liked the color and mouthfeel attributes, their hedonic impression of flavor attribute was slightly low due to unpalatable bitter note caused by the presence of the peptide. Incorporation of the pentapeptide in spray-dried orange juice has the potential to serve as a functional food ingredient that can offer health benefits to consumers. It is possible that the structural instability can be minimized by encapsulation.

Electrostatic spraying of organic acids on biofilms formed by E. coli O157:H7 and Salmonella Typhimurium on fresh produce.

Electrostatic spraying which has an even and retained surface coverage could be an effective novel technique to completely cover the surface of fresh produce to disrupt biofilm formation by pathogenic bacteria. Spinach leaves and cantaloupe rind were spot-inoculated with a bacterial culture and stored at 8°C for 72h to allow biofilm formation. Among various green fluorescent protein-labeled strains, ED 14 strain of E. coli O157:H7 and SD 10strain of Salmonella Typhimurium had the best attachment based on colony counts. The produce samples were electrostatically sprayed with malic (MA) and lactic (LA) acid solutions alone (1.0/2.0/3.0/4.0% w/v) or in combination (0.5+0.5/1.0+1.0/1.5+1.5/2.0+2.0% w/v) to test for a reduction in the attached bacteria. A combined treatment of LA 2.0% w/v+MA 2.0% w/v had the highest log reduction (CFU/disk) of 4.14 and 3.6 on the attached E. coli strain ED 14 (spinach) and Salmonella strain SD 10 (cantaloupe), respectively. Crystal violet assay demonstrated the disruptive effect of organic acids on biofilms formed by the pathogenic bacteria. Application of electrostatic spray with a combination of malic and lactic acids resulting in a log reduction (CFU/disk) of 3.6 or higher can improve the microbial safety of spinach and cantaloupe by preventing the pathogenic biofilm formation and bacterial growth.

Phenolics and antioxidant activity of Saskatoon berry (Amelanchier alnifolia) pomace extract.

Saskatoon berries (Amelanchier alnifolia Nutt.) have significantly higher levels of anthocyanins (ACY) among berries with potential health benefits. The pomace is a by-product of juice extracted from berries and is a potential source of inexpensive polyphenols. The objectives of this study were to extract the maximum amount of total phenolics from saskatoon pomace, to determine the antioxidant activity, and to identify individual phenolic components. Pomace extracts showed high content of total phenolics, total ACY, and total flavonoids of 43.3, 2.8, and 10.3 g/kg of dried weight (DW) of pomace. A high oxygen radical absorbing capacity value of 119.4 µmol Trolox equivalents/g DW and free radical scavenging activity of pomace extract (200 ppm, 86.8%) were observed. Five major ACY, two flavonols, and three chlorogenic acids were identified and quantified in pomace extracts. This study shows that saskatoon berries pomace rich in antioxidant phenolics could be extracted by "green" solvents (water and ethanol) and used as suitable food product applications.

Functional properties and Angiotensin-I converting enzyme inhibitory activity of soy-whey proteins and fractions.

Soy proteins when prepared to high purity can confer good functional properties and the whey by-product is a potential source for bioactivity. In this study, we determined the protein, moisture, fiber, solubility, foaming, emulsion properties, as well as Angiotensin-I converting enzyme (ACE-I) inhibitory activity of prepared soy-whey proteins and its fractions. The soy-whey proteins were fractionated into <5, >5, >10, and >50kDa using ultrafiltration. The expanded AACC methods were used to determine protein, moisture, and fiber analyses of the whey and its fractions. Solubility method was conducted to determine the protein solubility profile of the soy-whey and its fractions at varying pHs. Turbidimetric method was used to evaluate emulsifying activity (EA) and emulsion stability (ES). There were significant differences observed in moisture, protein and salt contents between unfractionated, >50kDa and smaller sized fractions. No significant differences were observed with phytic acid and total dietary fiber contents among all samples. The unfractionated whey protein and >50kDa fraction showed better solubility than other fractions. Unfractionated whey protein had the highest foam capacity (42.7mL) while the fraction >5kDa showed the greatest foaming stability (46min). The highest emulsion activity (0.33±0.1) and stability (825.1±45.1) was obtained with the >50kDa fraction while the unfractionated whey protein had the highest ACE-I inhibition activity. The findings indicate that soy-whey protein fraction (>50kDa) had good solubility, emulsion activity and stability, while the unfractionated whey protein exhibited the strongest ACE-I inhibition percentage (19%).