Planting seeds for the future of food

The health and wellbeing of future generations will depend on humankind's ability to deliver sufficient nutritious food to a world population in excess of 9 billion. Feeding this many people by 2050 will require science‐based solutions that address sustainable agricultural productivity and enable healthful dietary patterns in a more globally equitable way. This topic was the focus of a multi‐disciplinary international conference hosted by Nestlé in June 2015, and provides the inspiration for the present article. The conference brought together a diverse range of expertise and organisations from the developing and industrialised world, all with a common interest in safeguarding the future of food. This article provides a snapshot of three of the recurring topics that were discussed during this conference: soil health, plant science and the future of farming practice. Crop plants and their cultivation are the fundamental building blocks for a food secure world. Whether these are grown for food or feed for livestock, they are the foundation of food and nutrient security. Many of the challenges for the future of food will be faced where the crops are grown: on the farm. Farmers need to plant the right crops and create the right conditions to maximise productivity (yield) and quality (e.g. nutritional content), whilst maintaining the environment, and earning a living. New advances in science and technology can provide the tools and know‐how that will, together with a more entrepreneurial approach, help farmers to meet the inexorable demand for the sustainable production of nutritious foods for future generations. © 2015 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Initial screening for inhibitory activity of essential oils on growth of Fusarium verticillioides, F. proliferatum and F. graminearum on maize-based agar media

An in vitro initial screening of a range of 37 essential oils on inhibition of mycelial growth of Fusarium verticillioides, F. proliferatum and F. graminearum under different temperature (20–30°C) and water activity (a_w) (0.95–0.995) conditions was made. The basic medium was a 3% maize meal extract agar. The maize meal agar was modified with glycerol to a range of water activity conditions and the essential oils were incorporated at different concentrations (0, 500, 1000 μg ml⁻¹). Cinnamon leaf, clove, lemongrass, oregano and palmarosa oils were the products tested suitable for being used as novel preservatives in the control of the three Fusarium species studied. Although water activity was determinant for the growth of the isolates, in general, the preservative effects of the oils were not linked to a_w. However, a trend to a higher inhibition by the oils when a_w was low was observed. Temperature had a minor importance in the inhibitory effect of the preservatives. In vivo studies may be required to confirm the usefulness of the results obtained.     

Preservation of protective capacity of hyperimmune anti-Stx2 bovine colostrum against enterohemorrhagic Escherichia coli O157:H7 pathogenicity after pasteurization and spray-drying processes

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major etiologic agent that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Shiga toxin (Stx) is the main virulence factor of EHEC responsible for the progression to HUS. Although many laboratories have made efforts to develop an effective treatment for Stx-mediated HUS, a specific therapy has not been found yet. Human consumption of bovine colostrum is known to have therapeutic effects against several gastrointestinal infections because of the peptide and proteins (including antibodies) with direct antimicrobial and endotoxin-neutralizing effects contained in this fluid. We have previously demonstrated that colostrum from Stx type 2 (Stx2)-immunized pregnant cows effectively prevents Stx2 cytotoxicity and EHEC O157:H7 pathogenicity. In this study we evaluated the preservation of the protective properties of hyperimmune colostrum against Stx2 (HIC-Stx2) after pasteurization and spray-drying processes by performing in vitro and in vivo assays. Our results showed that reconstituted HIC-Stx2 colostrum after pasteurization at 60°C for 60 min and spray-dried under optimized conditions preserved specific IgG that successfully neutralized Stx2 cytotoxicity on Vero cells. Furthermore, this pasteurized/dehydrated and reconstituted HIC-Stx2 preserved the protective capacity against EHEC infection in a weaned mice model. The consumption of hyperimmune HIC-Stx2 bovine colostrum could be effective for HUS prevention in humans as well as in EHEC control in calves. However, further studies need to be done to consider its use for controlling EHEC infections.     

Effect of time and temperature on bioactive compounds in germinated Brazilian soybean cultivar BRS 258

The objective was to determine the effect of time and temperature on the concentration of bioactive compounds during germination of Brazilian soybean cultivar BRS 258. The concentration of bioactive compounds was optimized using Response Surface Methodology, with a 2² central composite rotational design and germination time and temperature as independent variables. Germination was carried out in a germination chamber, using paper in trays containing 500 g of seeds. Germination temperature and time modified the concentrations of bioactive compounds within the ranges studied. An increase in germination time at 25 °C decreased the concentration of Bowman–Birk inhibitor, lectin and lipoxygenase. After 63 h of germination, a temperature increase from 20 °C to 30 °C resulted in a decrease of lipoxygenase activity by 22.5%. Optimal increases in the concentrations of isoflavone aglycones (daidzein and genistein) and saponin glycosides were observed with a 63 h germination time at 30 °C. Both germination time and temperature had an influence on the composition and concentration of bioactive compounds in germinated soybean flour. Equations determined can be used to predict concentrations of bioactive compounds in germinated soybeans in relation to climate changes and thus optimize their potential use in human health and nutrition.     

Macedovicin,the second food-grade lantibiotic produced by Streptococcus macedonicus ACA-DC 198

Streptococcus macedonicus ACA-DC 198 was found to produce a second lantibiotic named macedovicin in addition to macedocin. Macedovicin was purified to homogeneity and mass spectrometric analysis identified a peptide of approximately 3.4 kDa. Partial N-terminal sequence analysis and tandem mass spectrometry revealed that macedovicin was identical to bovicin HJ50 and thermophilin 1277 produced by Streptococcus bovis and Streptococcus thermophilus, respectively. Macedovicin inhibits a broad spectrum of lactic acid bacteria, several food spoilage species (e.g. Clostridium spp.) and oral streptococci. We determined the complete biosynthetic gene cluster of macedovicin. Even though the gene clusters of macedovicin, thermophilin 1277 and bovicin HJ50 were almost identical at the nucleotide level, there were important differences in their predicted genes and proteins. Bovicin HJ50-like lantibiotics were also found to be encoded by Streptococcus suis strains SC84 and D12, Enterococcus columbae PLCH2, Clostridium perfringens JGS1721 and several Bacillus strains. All these lantibiotics contained a number of conserved amino acids that may be important for their biosynthesis and activity, while phylogenetic analysis supported their dispersion by horizontal gene transfer. In conclusion, the production of multiple bacteriocins may enhance the bio-protective potential of S. macedonicus during food fermentation.     

Efficacy of sanitizers to inactivate Escherichia coli O157:H7 on fresh-cut carrot shreds under simulated process water conditions

Chlorine is widely used as a sanitizer to maintain the microbial quality and safety of fresh-cut produce; however, chlorine treatment lacks efficacy on pathogen reduction, especially when the fresh-cut processing water contains heavy organic loads. A more efficacious sanitizer that can tolerate the commercial processing conditions is needed to maintain microbial safety of fresh-cut produce. This study evaluated the efficacy of Escherichia coli O157:H7 reduction on fresh-cut carrots using new and traditional sanitizers with tap water and fresh-cut processing water scenarios. Fresh-cut carrot shreds inoculated with E. coli O157:H7 were washed in sanitizer solutions including 200 ppm chlorine, citric acid-based sanitizer (Pro-San), 80 ppm peroxyacetic acid-based sanitizer (Tsunami 100), and 1,000 ppm acidified sodium chlorite (SANOVA) prepared in fresh tap water or simulated processing water with a chemical oxygen demand level of approximately 3,500 mg/liter. Samples were packaged and stored at 5 degrees C. Microbial analyses performed at days 0, 7, and 14 indicate that the organic load in the process water significantly affected the efficacy of chlorine on pathogen removal and was especially evident on samples tested during storage. Acidified sodium chlorite provided a strong pathogen reduction even under process water conditions with up to a 5.25-log reduction when compared with the no-wash control. E. coli O157:H7 was not recovered on acidified sodium chlorite-treated samples during the entire 14 days of storage, even following an enrichment step. These results suggest that acidified sodium chlorite holds considerable promise as an alternative sanitizer of fresh-cut produce.     

Antioxidant and cardioprotective effects of Ilex brasiliensis: A comparative study with Ilex paraguariensis (yerba mate)

Our objective was to compare the antioxidant properties and cardiovascular effects in ischemia–reperfusion of leaves aqueous extracts of Ilex brasiliensis (B) and Ilex paraguariensis (P). In vitro systems were used to assess the antioxidant properties of the extracts. Isolated rat hearts were treated with both extracts before ischemia and myocardial function was assessed. Thiobarbituric acid reactive substances (TBARS) concentration and reduced glutathione (GSH) were also measured. B extract showed higher total phenols and ascorbic acid contents and a higher scavenging activity of peroxynitrite and ferric reducing antioxidant power (FRAP) than P extract. Postischemic systolic and diastolic functions were improved after B and P treatment. Both extracts decreased TBARS and preserved GSH content.The present study demonstrates that an aqueous extract of I. brasiliensis, similar to I. paraguariensis, protects the myocardium against ischemia–reperfusion injury and attenuates oxidative damage. These effects may be attributed to the potent antioxidant properties of the extract.     

Thermal, high pressure, and electric field processing effects on plant cell membrane integrity and relevance to fruit and vegetable quality

Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (1H-NMR).     

Effect of ractopamine–HCl supplementation for 28 days on carcass characteristics,muscle fiber morphometrics,and whole muscle yields of six distinct muscles of the loin and round

This study evaluated the effects of ractopamine–HCl (RAC) supplementation on carcass characteristics, muscle fiber morphometrics, and tenderness. Thirty-four steers (2 groups, 4 replicates) were fed RAC or carrier for 28 days prior to harvest. Seventy-two hours postmortem, the Longissimus lumborum (LL), Gracilis (GRA), Vastus lateralis (VL), Rectus femoris (RF), Semimembranosus (SM), and Adductor (ADD) were dissected from each carcass. Commodity weight, denuded weight, and muscle dimensions were collected. RAC supplementation tended to affect dressing percentage (P = 0.15) and muscle firmness (P < 0.15), and significantly affected lean maturity (P < 0.05) and marbling score (P < 0.05). With the exception of the LL and GRA (P < 0.05), RAC had no effect on muscle dimensions. RAC did not influence the tenderness of vacuum-packaged, aged steaks as measured by Warner–Bratzler shear force. Muscle fiber size within the six muscles was unchanged (P > 0.05) by RAC. Thus, RAC improves carcass parameters without a negative impact on tenderness.