Effect of Hydrogen Peroxide Pretreatment on Physiological and Biochemical Variables during Germination of Alfalfa Seeds

Background: Hydrogen peroxide is reactive oxygen species that plays role in plant response to biotic and abiotic stress. The pretreatment with hydrogen peroxide can confer an adaptive capacity for the plants in unpredictable environments. The alfalfa (Medicago sativa L.) is the legume more utilized in animal feeding in the world. Moreover, the alfalfa sprouts are known for the phytochemicals that promote health with antioxidant properties. Methods: This work aimed to determine the effect of hydrogen peroxide in the pretreatment process of alfalfa seeds on variables as total germination, speed of germination, activity and antioxidant enzymes. The alfalfa seeds were soaked for 12 h in the next treatments 0, 98, 294, 490, 784, 980 mM of hydrogen peroxide. Result: The results showed that total germination was higher with the hydrogen peroxide than with water except 980 mM. The results of the present research indicated that hydrogen peroxide had physiological and biochemical effects on the germination processes of alfalfa.

Effect of Germination on Alfalfa and Buckwheat: Phytochemical Profiling by UHPLC-ESI-QTOF-MS/MS, Bioactive Compounds, and In-Vitro Studies of Their Diabetes and Obesity-Related Functions

Germination can be used to enhance nutritional value and health functions of edible seeds. Sprouts are considered healthier than raw seeds because they are richer in the basic nutritional components (carbohydrates, protein, vitamins, and minerals) and also contain more bioactive components responsible for various biological activities. The effect of sprouting on the antioxidant, antidiabetic, antiobesity activities, and metabolite profiles of alfalfa and buckwheat seeds was investigated in this study. DPPH radical scavenging activity was highest in buckwheat sprouts followed by alfalfa sprout, buckwheat seed, and alfalfa seed, respectively. ABTS radical scavenging potential showed a similar trend as DPPH with buckwheat sprouts exerting the best scavenging capacity. Alfalfa sprout and buckwheat seed exhibited the highest percentage inhibitory activity of α-glucosidase (96.6 and 96.5%, respectively). Alfalfa sprouts demonstrated the strongest inhibitory activity against pancreatic lipase (57.12%) while alfalfa seed showed the highest advanced glycation end products (AGEs) formation inhibitory potential (28.7%). Moreover, thirty-three (33) metabolites were characterized in the seed and sprout samples. Sprouts demonstrated a higher level of metabolites compared to raw seeds. Hence, depending on the type of seed and the target activity, sprouting is a good technique to alter the secondary metabolites and functional properties of edible seeds.

Detection of Campylobacter jejuni from fresh produce: comparison of culture- and PCR-based techniques, and metagenomic approach for analyses of the microbiome before and after enrichment

In this study, we compared the efficiency of culture-based methods with or without membrane filtration, real-time PCR and digital droplet PCR (ddPCR) for the detection of Campylobacter in fresh produce. Alfalfa sprouts, clover sprouts, coleslaw, and lettuce salad spiked with Campylobacter jejuni ( C. jejuni ) were enriched in Bolton broth for 48 h and enrichment cultures were either directly inoculated onto modified charcoal-cefoperazone-deoxycholate agar or applied on membrane filters placed on the surface of plating media. In parallel, 2 mL Bolton broth cultures were taken to extract DNA for real-time and ddPCR assays and bacterial community analysis. There was no significant difference ( p > 0.05) in the detection efficiency of positive Campylobacter isolates from coleslaw and lettuce salad using four detection methods. However, for sprout samples, the detection efficiency of the culture method was significantly ( p < 0.05) lower than those of the two PCR assays and the filtration method. The analysis also revealed the presence of Pseudomonas and Acinetobacter as the most prevalent competing microbiota in enriched culture and only Acinetobacter on agar plates in the selective culture step.

Effect of Elicitation with Iron Chelate and Sodium Metasilicate on Phenolic Compounds in Legume Sprouts

Seven-day-old sprouts of fenugreek (Trigonella foenum-graecum L.), lentil (Lens culinaris L.), and alfalfa (Medicagosativa L.) were studied. The legume seeds and then sprouts were soaked each day for 30 min during 6 days with water (control) or mixture of Fe-EDTA and sodium silicate (Optysil), or sodium silicate (Na-Sil) alone. Germination and sprout growing was carried out at temperature 20 ± 2 °C in 16/8 h (day/night) conditions. Phenolic compounds (free, ester, and glycosides) content were determined by HPLC-ESI-MS/MS using a multiple reaction monitoring of selected ions. Flavonoids and phenolic acids were released from their esters after acid hydrolysis and from glycosides by alkaline hydrolysis. The presence and high content of (−)-epicatechin (EC) in fenugreek sprouts was demonstrated for the first time. Applied elicitors decreased the level of free EC in fenugreek and alfalfa sprouts but enhanced the content of its esters. Besides, elicitors decreased the content of quercetin glycosides in lentil and fenugreek sprouts but increased the content of quercetin and apigenin glycosides in alfalfa sprouts. The applied elicitors decreased the glycoside levels of most phenolic acids in lentil and p-hydroxybenzoic acid in fenugreek, while they increased the content of this acid in alfalfa. The mixture of iron chelate and sodium silicate had less effect on changes in flavonoid and phenolic acid content in legume sprouts than silicate alone. In general, the used elicitors increased the content of total phenolic compounds in fenugreek and alfalfa sprouts and decreased the content in lentil sprouts. Among the evaluated elicitors, Optysil seems to be worth recommending due to the presence of iron chelate, which can be used to enrich sprouts with this element.

Water Microbiota from a Commercial Alfalfa Sprout Crop over 4 Days of Growth

ABSTRACT Sprouts have been implicated in numerous foodborne illness outbreaks. To better understand baseline microbial profiles of irrigation water and subsequent spent irrigation water of alfalfa sprouts, DNA from water was extracted, sequenced, and annotated with CosmosID and a custom pipeline to provide bacterial, fungal, protist, and antimicrobial resistance gene profiles.

Antibacterial Effect of a Copper Surface in the Germination of Alfalfa Seeds (Medicago sativa L.)

Copper metal as a contact surface was studied during the germination of alfalfa seeds (Medicago sativa L.) inside a rotating drum on a laboratory scale and compared with a plastic surface of food-grade. A system of three rotating drums was used inside a thermo-regulated chamber to germinate seeds. Alfalfa seeds were inoculated with 4.2 log cfu g-1 of Escherichia coli and after 84 h of germination sprouts were evaluated for E. coli, mesophilic aerobic bacteria, the content of copper and other minerals (potassium, calcium, magnesium, sodium, iron, manganese, and zinc), total mass, unit mass and length, and color. The contact of alfalfa sprouts with copper sheets allowed to reduce the E. coli load from 6.54 to <0.1 log cfu g-1. However, all sprouts exceeded in copper (> 10 ppm) according to Food Sanitary Regulations. Germinated mass and length decreased after copper treatments. No statistically significant differences were observed between treatments for the remaining quality parameters. Finally, it is concluded that copper was very efficient in reducing the microbial load of E. coli in alfalfa sprouts, complying with the regulations established by the Chilean Ministry of Health.

Comparative Study of the Bioactive Properties and Elemental Composition of Red Clover (Trifolium pratense) and Alfalfa (Medicago sativa) Sprouts during Germination

Considering the growing interest in functional foods, the identification of the individual species of elements is of great importance in understanding specific nutraceutical properties. The present study aims to compare the dynamic of the elemental content (K, Na, Ca, Mg, Fe, Cu, Zn, Mn, Ni, and Se), total polyphenols, and antioxidant activity of Trifolium pratense L. and Medicago sativa L. sprouts in different germination stages. The elemental profile was established by atomic absorption spectroscopy after the microwave acid digestion of the samples, while total polyphenols and anti-radical activity were evaluated by UV-Vis spectroscopic methods. Phenolic compounds and anti-radical activity of both alfalfa and red clover sprouts varied with germination stages. Germination can significantly increase the anti-radical activity in the first 3 days of germination, followed by a decline in the following days. An increase in total polyphenols was noticed, starting from the second day of germination in both plant species. There were significant (p < 0.05) differences for Ca, Na, Fe, K, Zn, and Mg contents among the sprouts, depending on the germination stage and plant species. The calcium contents of alfalfa ranged between 200.74 µg/g DW (raw seeds) and 2765.31 µg/g DW (sprouted), while in red clover between 250.83 µg/g DW and 601.59 µg/g DW. Maximum selenium content in alfalfa sprouts, reached in the 3rd day of germination (11.42 µg/g DW), exceeded the maximum value measured in red clover (9.42 µg/g DW). The data were subject to statistical processing using analysis of variance (ANOVA), multivariate analysis (PCA) and hierarchical clustering analysis (HCA).

The Evaluation of Antibacterial Activity of Copper Sheets in the Germination of Alfalfa Seeds (Medicago sativa L.) within a Rotating Drum

— The consumption of sprouts in the human diet has grown during the last years, but great concern raised from public health institutions, food industry and consumers regarding their safety since foodborne diseases caused by microorganisms have been reported. Copper metal as a contact surface was studied during the germination of alfalfa seeds (Medicago sativa L.) inside a rotating drum on a laboratory scale and compared with a plastic surface of food-grade. A system of three rotating drums was used inside a thermo-regulated chamber to germinate seeds. To evaluate the antibacterial activity of copper sheets, alfalfa seeds were inoculated with 4.2 log cfu g-1 of Escherichia coli and after 84 hours of germination sprouts were evaluated for E. coli, mesophilic aerobic bacteria, the content of copper and other minerals (potassium, calcium, magnesium, sodium, iron, manganese, and zinc), total mass, unit mass and length, and color. The contact of alfalfa sprouts with copper sheets allowed to reduce the E. coli load from 6.54 to <0.1 log cfu g-1. However, all sprouts exceeded in copper (> 10 ppm) according to Food Sanitary Regulations. Germinated mass and length decreased after copper treatments. No statistically significant differences were observed between treatments for the remaining quality parameters. Finally, it is concluded that copper was very efficient in reducing the microbial load of E. coli in alfalfa sprouts, complying with the regulations established by the Chilean Ministry of Health.