Preliminary Research on the Influence of a Pulsed Magnetic Field on the Cationic Profile of Sunflower, Cress, and Radish Sprouts and on Their Germination Rate

Magnetic stimulation of seeds before sowing can have a significant impact on the speed of their germination. Sprouts are sought after by consumers for their high nutrient content. The purpose of the study was to investigate the influence of a pulsed magnetic field on the dynamics of seed germination and on the content of ions in sunflower, cress, and radish sprouts. The research material in the experiment was provided by seeds of sunflower (Helianthus annuus L.), garden cress (Lepidium sativum L.), and garden radish (Raphanus sativus L.) intended for sprouting, which were supplied by PNOS Ożarów Mazowiecki. The research methods involved germinating seeds under strictly defined conditions for 14 days. Then, the mineral composition of the previously mineralised sprout material was determined using emission spectrometry on a ICP-OES iCAP Duo 6500 Termo spectrometer. Greater dynamics of germination were noted in the first half of the growth period in seeds stimulated with a pulsed magnetic field with the parameters 100 µT and 100 Hz. However, the application of the magnetic field produced no increase in the capacity of the seeds to germinate. The research showed an increase in the content of macronutrients in sprouts, such as calcium, magnesium, phosphorus, and sulphur. In the case of the field with parameters of 100 µT and 200 Hz, the effect was similar for both the germination percentage and the accumulation of macronutrients. However, in the case of both frequencies of magnetic field applied, the effect on individual plant seed species was different. Pre-sowing stimulation of seeds with a pulsed magnetic field may affect the rate of seed germination and the content of ions in the sprouts; however, these effects vary in individual plant matrices.

The Antioxidant Properties and Biological Quality of Radish Seedlings Biofortified with Iodine

Iodine is an essential trace element for humans, and iodine deficiency is a significant health problem. In this study, an improved method for iodine biofortification based on seed germination was established. Solutions of KI (0.15, 0.30, 0.75 and 1.5 mg∙g−1 of seeds) were applied to germinating radish seeds of two cultivars Raphanus sativus L. var. sativus: Warta and Zlata. Compared with the control (seeds treated with water) the iodine content (in the radish sprouts produced by germinating seeds treated with KI were approximately 112.9–2730 times higher. The application KI rates did not adversely affect the biological quality of the radish sprouts. Regarding the biological quality of the iodine-enriched seedlings, we determined their length, dry mater, protein, soluble sugars, chlorophylls, total phenol, ascorbic acid, thiol group content and total antioxidant capacity. The effect of potassium iodide on the selected parameters of their biological quality varied depending on the KI doses and radish cultivars. The results showed that the most appropriate biofortification application rates were 0.15 and 0.30 mg KI per g seeds, because the enriched seedlings had excellent biological quality parameters.

The Application of Fe-EDTA and Sodium Silicate Affects the Polyphenols Content in Broccoli and Radish Sprouts

The effects of elicitors on broccoli (Brassica oleracea L. var. Italica) and radish (Raphanus sativus L.) sprouts were evaluated. Seeds and then sprouts were soaked daily for 30 min over 6 days in water (control) or a mixture of FeEDTA and sodium silicate or sodium silicate alone. The contents of the flavonoids and phenolic acids (free, esters, and glycosides) were determined using HPLC-ESI-MS/MS. Phenolic compounds were released from the esters after acid hydrolysis and from the glycosides using alkaline hydrolysis. Quercetin, kaempferol, (‒)-epicatechin, naringenin, apigenin, and luteolin derivatives were found in broccoli and radish sprouts, while derivatives of iso-rhamnetin, orientin, and vitexin were not present at measurable levels. The flavonoid contents, especially derivatives of quercetin, were considerably higher in the broccoli sprouts than in the radish sprouts. The quantitatively major phenolic acid content in the sprouts of both species was found to be p-hydroxybenzoic acid. Its content in the radish sprouts was several times higher than in the broccoli sprouts. The total flavonoid content of broccoli sprouts was 507–734 µg/g DW, while that of the radish sprouts ranged from 155 µg/g DW to 211 µg/g DW. In contrast, total phenolic acids were higher in radish sprouts, ranging from 11,548 to 13,789 µg/g DW, while in broccoli sprouts, they ranged from 2652 to 4527 µg/g DW, respectively. These differences resulted radish sprouts having higher antioxidant activity compared to broccoli sprouts. The applied elicitors increased the content of the total phenolic acids and the antioxidant activity of radish and broccoli sprouts, while they decreased the level of the total flavonoids in broccoli sprouts.

Use of Phage Cocktail for Improving the Overall Microbiological Quality of Sprouts—Two Methods of Application

Background: the aim of this study was to improve the overall microbiological quality of five different sprouts (alfalfa, kale, lentil, sunflower, radish) using newly isolated bacteriophages. Method: in this study we had isolated from sewage 18 bacteriophages targeting bacteria dominant in sprouts. Five selected bacteriophage strains were photographed using a transmission electron microscope (TEM), and we analyzed the rate of attachment, resistance to chloroform, the burst size, and the latency period. Two methods of application of the phage cocktail were investigated: spraying, and an absorption pad. Results: the spraying method was significantly more efficient, and the maximum reduction effect after 48 h of incubation was 1.5 log CFU/g. Using pads soaked with phage lysate reduced the total number of bacteria to only about 0.27–0.79 log CFU/g. Conclusion: the reduction of bacteria levels in sprouts depended on the method of phage application. The blind strategy for searching phage targeting bacteria dominant in sprouts can be useful and economically beneficial as a starting point for further investigation in phage cocktail application for improving the overall microbiological quality of food. The main result of our research is to improve the overall quality of kale and radish sprouts by spraying them with a phage cocktail.

Evaluation of ceftazidime as an antibiotic supplement of mannitol-yolk-polymyxin B agar used for the enumeration of Bacillus cereus in ready-to-eat vegetables

Bacillus cereus, which causes foodborne disease, is detected using selective media. However, competing flora is the most common factor preventing the correct enumeration of B. cereus on selective agars. In this study, we aimed to improve the selectivity of mannitol-yolk-polymyxin B agar (MYPA) and its modified version containing trimethoprim (mMYPA) developed in our previous study by supplementation with ceftazidime (16 μg/mL). Ceftazidime-supplemented MYPA (C-MYPA16) and mMYPA (C-mMYPA16) were evaluated for bacteria recoverability and selectivity using three types of ready-to-eat vegetables. Four B. cereus and one B. thuringiensis strains were mixed and artificially inoculated into vegetable salad, radish sprouts, and sprout mix, and then recovered using MYPA, mMYPA, C-MYPA16, and C-mMYPA16. In all tested vegetables, mMYPA, C-MYPA16, and C-mMYPA16 exhibited similar recoverability of B. cereus / thuringiensis ( p > 0.05), whereas MYPA showed undistinguishable colonies in case of radish sprouts and sprout mix. At the same time, C-mMYPA16 provided the best selectivity compared with the other agars because it eliminated most of competing flora in the tested vegetables, especially in sprouts, without negatively affecting the recovery of B. cereus / thuringiensis . Our results indicate that the supplementation of mMYPA with ceftazidime may improve medium selectivity for B. cereus / thuringiensis in food testing.

Prevalence and molecular characterization of Escherichia coli isolates during radish sprout production in the Republic of Korea

This study was conducted to investigate the prevalence of coliforms and Escherichia coli across radish sprout production facilities in the Republic of Korea and to characterize isolated E. coli. A total of 324 samples were collected from three different radish sprout production units in spring and summer. Overall, the levels of coliforms were significantly higher (> 3.75 log CFU/g) in radish sprouts during summer season than in spring. E. coli was detected in the pre-harvest (50%) and post-harvest (39%) sprouts and water samples (33%) from farms B and C. Of the 48 E. coli isolates, five E. coli isolates were positive for the eaeA gene, indicative of EPEC O110, two isolates were eaeA-positive (EPEC ONT) and one isolate was ipaH-positive (ETEC O71). These three E. coli strains were identified as novel sequence types by the multilocus sequence-typing assay based on the combination of allelic profiles. In addition, the EPEC O110 isolates obtained from the stream water stored in container of farm C were toxic to Caenorhabditis elegans. It is necessary to implement safety measures during the production of radish sprouts to prevent E. coli outbreaks.

Improving the Anthocyanin Accumulation of Hypocotyls in Radish Sprouts by Hemin-induced NO

Background: The biosynthesis of anthocyanin in the hypocotyls of radish (Raphanus sativus L.) sprouts was enhanced by hemin in our preliminary experiments, but the underlying mechanism is unclear. Here, we found that NO (nitric oxide) exerted an essential role in Hemin-regulated anthocyanin biosynthesis, which was supported by the following results.Results: Hemin boosted anthocyanin as well as NO content. NO-scavenger cPTIO (carboxy-PTIO) significantly attenuated hemin-induced increase of anthocyanin content, transcripts of anthocyanin synthesis related genes and positive transcription factors, implying that NO played a prominent role during hemin-induced anthocyanin biosynthesis. Hemin specific inhibitor ZnPP (Zinc Protoporphyrin) strongly reduced anthocyanin content, while, NO donor SNP (Sodium Nitroprusside) addition considerably reversed this inhibition and by contrast, resulted in a significant increase in anthocyanin accumulation, closely paralleling the transcripts of structural genes and transcription factors. Moreover, NO content, NR (nitrate reductase) activity and expression level of NOA (nitric oxide associated factor) were up-regulated by Hemin. Conclusions:Those consequences indicated that NO might work downstream in Hemin-heightened anthocyanin accumulation in radish sprouts.

Effects of aquaponic system on growth and nutrients content and sustainable production of sprouts in urban area

An aquaponic system in urban area was designed and combined fish culture with sprouts production in a closed-loop system that mimics the ecology of the nature. In order to quantify the nutrients content of sprouts grown under different conditions, we conducted a factorial experiment with 3 types of growth conditions, routine cultivation (RC), circulating water supplement cultivation (CWSC) and aquaponic system cultivation (ASC), then produce sprouts (soybean sprouts, mung bean sprouts, pea sprouts and radish sprouts) under these conditions. The results showed that each sprout under ASC condition, height, weight (10 sprouts), vitamin C content, protein content and soluble sugar content were significantly higher than those under RC condition and CWSC condition. Each sprout showed significant difference in height, weight (10 sprouts), vitamin C content and soluble sugar content. The presence of Carassius auratus auratus can significantly promote the growth of sprouts in aquaponic system, and increase nutrients content. Therefore, aquaponic system can be promoted vigorously in urban areas