Foods, Volume 6, Issue 8 (August 2017) – 16 articles

Anchote (Coccinia abyssinica) is an indigenous tuber crop of the Ethiopian Highlands. It is popular in the western Oromia Region of the country. Apart from food, the crop is also used in traditional medicine. Anchote tubers possess two variations in its tissue colour, red and white. In this study, a small market survey and a nutritional comparison of red and white anchote were conducted. White tissue anchote seems to be more popular, due to its soft texture and ease of cooking. However, the red variant was considered for flour making (by dehydration), for use in porridge and soups for various medicinal and supplementary food applications. Red anchote tubers contained significantly higher protein content (16.85 mg/100 g dry matter basis) than the white variant. However, apart from the marginally higher protein content compared to other tropical root and tuber crops, anchote seems to remain a primary source of carbohydrates. In macro minerals, white anchote proves to be a more important source of Ca with 81 mg/100 g edible portion; however, on dry matter basis, the content was similar to the red variant (316 and 309 mg/100 g dry matter, white and red respectively). Further research on vitamin content (especially vitamin A in the red variant) would be useful to understand the full nutrition potential of the crop. Full article

Food commonly is associated with emotion. The study was designed to determine if a spice blend (cinnamon, ginger, nutmeg, and cloves) high in antioxidants can evoke changes in consumer emotions. This was an exploratory study to determine the effects of these four spices on emotions. Three extruded, dry snack products containing 0, 4, or a 5% spice blend were tested. One day of hedonic and just-about-right evaluations (n = 100), followed by three days of emotion testing were conducted. A human clinical trial (n = 10), using the control and the 4% samples, measured total antioxidant capacity and blood glucose levels. The emotion “Satisfied” increased significantly in the 5% blend, showing an effect of a higher spice content. The 4% blend was significantly higher in total antioxidant capacity than the baseline, but blood glucose levels were not significantly different. Full article

Beef safety may be compromised by O157 and non-O157 Shiga toxin-producing Escherichia coli (STEC) contamination. The capacity of surfactant micelles loaded with the plant-derived antimicrobial eugenol to reduce STEC on beef trimmings that were later ground and refrigerated for five days at 5 ± 1 °C was tested to determine their utility for beef safety protection. STEC-inoculated trimmings were treated with free eugenol, micelle-encapsulated eugenol, 2% lactic acid (55 °C), sterile distilled water (25 °C), or left untreated (control). Following treatment, trimmings were coarse-ground and stored aerobically at 5 ± 1 °C. Ground beef was then sampled for STEC immediately post-grinding, and again at three and five days of storage. STEC minimum inhibitory concentrations (MICs) in liquid medium for free eugenol and 1% sodium dodecyl sulfate (SDS)-loaded micelles were 0.5% and 0.125%, respectively. STEC numbers on beef trimmings treated by sterile water (6.5 log₁₀ CFU/g), free eugenol (6.5 log₁₀ CFU/g), micelle-loaded eugenol (6.4 log₁₀ CFU/g), and lactic acid (6.4 log₁₀ CFU/g) did not differ compared to untreated controls (6.6 log₁₀ CFU/g) (p = 0.982). Conversely, STEC were significantly reduced by refrigerated storage (0.2 and 0.3 log₁₀ CFU/g at three and five days of storage, respectively) (p = 0.014). Antimicrobial treatments did not significantly decontaminate ground beef, indicating their low utility for beef safety protection. Full article

Active (anti-microbial) packaging was prepared using three different formulations; Auranta FV; Inbac-MDA and sodium octanoate at two concentrations (2.5 and 3.5 times their minimum inhibitory concentration (MIC, the lowest concentration that will inhibit the visible growth of the organisms) against Clostridium estertheticum, DSMZ 8809). Inoculated beef samples were packaged using the active packaging and monitored for 100 days storage at 2 °C for blown pack spoilage. The time to the onset of blown pack spoilage was significantly (p < 0.01) increased using Auranta FV and sodium octanoate (caprylic acid sodium salt) at both concentrations. Moreover, sodium octanoate packs had significantly (p < 0.01) delayed blown pack spoilage as compared to Auranta FV. It was therefore concluded that Auranta FV or sodium octanoate, incorporated into the packaging materials used for vacuum packaged beef, would inhibit blown pack spoilage and in the case of the latter, well beyond the 42 days storage period currently required for beef primals. Full article

The impact of sodium chloride (NaCl) concentration on the yeast activity in bread dough and its influence on the aroma profile of the baked bread was investigated. Key aroma compounds in the bread samples were analysed by two-dimensional high-resolution gas chromatography-mass spectrometry in combination with solvent-assisted flavour evaporation distillation. High-sensitivity proton-transfer-reaction mass spectrometry was used to detect and quantify 2-phenylethanol in the headspace of the bread dough during fermentation. The analyses revealed significant (p < 0.05) changes in the aroma compounds 2-phenylethanol, (E)-2-nonenal, and 2,4-(E,E)-decadienal. Descriptive sensory analysis and discriminating triangle tests revealed that significant differences were only determinable in samples with different yeast levels but not samples with different NaCl concentrations. This indicates that a reduction in NaCl does not significantly influence the aroma profile of yeasted bread at levels above the odour thresholds of the relevant compounds, thus consumers in general cannot detect an altered odour profile of low‑salt bread crumb. Full article

This review examines different nutritional guidelines, some case studies, and provides insights and discrepancies, in the regulatory framework of Food Safety Management of some of the world’s economies. There are thousands of fermented foods and beverages, although the intention was not to review them but check their traditional and cultural value, and if they are still lacking to be classed as a category on different national food guides. For understanding the inconsistencies in claims of concerning fermented foods among various regulatory systems, each legal system should be considered unique. Fermented foods and beverages have long been a part of the human diet, and with further supplementation of probiotic microbes, in some cases, they offer nutritional and health attributes worthy of recommendation of regular consumption. Despite the impact of fermented foods and beverages on gastro-intestinal wellbeing and diseases, their many health benefits or recommended consumption has not been widely translated to global inclusion in world food guidelines. In general, the approach of the legal systems is broadly consistent and their structures may be presented under different formats. African traditional fermented products are briefly mentioned enhancing some recorded adverse effects. Knowing the general benefits of traditional and supplemented fermented foods, they should be a daily item on most national food guides. Full article

This work aims to study the production of the biomass of S. cerevisiae on an optimized medium using date extract as the only carbon source in order to obtain a good yield of the biomass. The biomass production was carried out according to the central composite experimental design (CCD) as a response surface methodology using Minitab 16 software. Indeed, under optimal biomass production conditions, temperature (32.9 °C), pH (5.35) and the total reducing sugar extracted from dates (70.93 g/L), S. cerevisiae produced 40 g/L of their biomass in an Erlenmeyer after only 16 h of fermentation. The kinetic performance of the S. cerevisiae strain was investigated with three unstructured models i.e., Monod, Verhulst, and Tessier. The conformity of the experimental data fitted showed a good consistency with Monod and Tessier models with R² = 0.945 and 0.979, respectively. An excellent adequacy was noted in the case of the Verhulst model (R² = 0.981). The values of kinetic parameters (Ks, X_m, μ_m, p and q) calculated by the Excel software, confirmed that Monod and Verhulst were suitable models, in contrast, the Tessier model was inappropriately fitted with the experimental data due to the illogical value of Ks (−9.434). The profiles prediction of the biomass production with the Verhulst model, and that of the substrate consumption using Leudeking Piret model over time, demonstrated a good agreement between the simulation models and the experimental data. Full article

Garlic, Allium sativum, is broadly used around the world for its numerous culinary and medicinal uses. Wild garlic, Allium vineale, has been used as a substitute for garlic, both in food as well as in herbal medicine. The present study investigated the chemical compositions of A. sativum and A. vineale essential oils. The essential oils from the bulbs of A. sativum, cultivated in Spain, were obtained by three different methods: laboratory hydrodistillation, industrial hydrodistillation, and industrial steam distillation. The essential oils of wild-growing A. vineale from north Alabama were obtained by hydrodistillation. The resulting essential oils were analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Both A. sativum and A. vineale oils were dominated by allyl polysulfides. There were minor quantitative differences between the A. sativum oils owing to the distillation methods employed, as well as differences from previously reported garlic oils from other geographical locations. Allium vineale oil showed a qualitative similarity to Allium ursinum essential oil. The compositions of garlic and wild garlic are consistent with their use as flavoring agents in foods as well as their uses as herbal medicines. However, quantitative differences are likely to affect the flavor and bioactivity profiles of these Allium species. Full article

In this study, the potential use of Moringa oleifera as a clotting agent of different types of milk (whole, skim, and soy milk) was investigated. M. oleifera seed extract showed high milk-clotting activity followed by flower extract. Specific clotting activity of seed extract was 200 times higher than that of flower extract. Seed extract is composed by four main protein bands (43.6, 32.2, 19.4, and 16.3 kDa). Caseinolytic activity assessed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and tyrosine quantification, showed a high extent of casein degradation using M. oleifera seed extract. Milk soy cheese was soft and creamy, while skim milk cheese was hard and crumbly. According to these results, it is concluded that seed extract of M. oleifera generates suitable milk clotting activity for cheesemaking. To our knowledge, this study is the first to report comparative data of M. oleifera milk clotting activity between different types of soy milk. Full article

Seasonal variation in conjugated linoleic acid (CLA) content and atherogenicity index (AI) of retail dairy products (whole milk, butter, and prato, a soft yellow cheese) from Brazil was investigated. CLA content of dairy products ranged from 0.55 to 1.53 g CLA/100 g fatty acids and was on average 25% higher during the rainy season compared to the dry season. Dairy products from the rainy season also had lower AI levels, indicating a lower risk of causing cardiovascular disease in consumers. This seasonality led to estimated seasonal variations of milk fat quality consumed by the population of southeastern Brazil, meaning 15% and 19% variation in daily intake of CLA and AI values, respectively. Dietary consumption of CLA (g/day) was greater in the rainy season, despite higher intake of dairy products during the dry season. We show that dairy products produced during the rainy season in Brazil are expected to be more beneficial to human health than are those produced during the dry season. Full article

Studies on methods for fixing foods (with a slight loss of bioactive compounds) and obtaining attractive products are important with respect to current technology. The drying process allows for a product with highly bioactive properties. Drying of Physalis fruit was carried out in a conventional manner, and in a microwave under reduced pressure at 120 W and 480 W. After drying, the fruits were subjected to strength and rheological tests. Water activity, content of carotenoids and polyphenols and antioxidant activity as well as colour were also examined. The study showed that Physalis is a difficult material for drying. The best results were obtained using microwave drying at a power of 480 W. Physalis fruit microwave-dried by this method is characterized by higher resistance to compression than the fruit dried by convection. Dried fruit obtained in this way was characterized by higher contents of bioactive compounds, better antioxidant properties, and at the same time the lowest water activity. Full article

In the organic food industry, no chemical additives can be used to prevent microbial spoilage. As a consequence, the essential oils (EOs) obtained from organic aromatic herbs and spices are gaining interest for their potential as preservatives. The organic Thymus zygis, Thymus mastichina, Thymus capitatus and Thymus vulgaris EOs, which are common in Spain and widely used in the meat industry, could be used as antibacterial agents in food preservation. The aims of this study were to determine (i) the antibacterial activity using, as culture medium, extracts from meat homogenates (minced beef, cooked ham or dry-cured sausage); and (ii) the antioxidant properties of organic EOs obtained from T. zygis, T. mastichina, T. capitatus and T. vulgaris. The antioxidant activity was determined using different methodologies, such as Ferrous ion-chelating ability assay, Ferric reducing antioxidant power, ABTS radical cation (ABTS^•+) scavenging activity assay and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method; while the antibacterial activity was determined against 10 bacteria using the agar diffusion method in different meat model media. All EOs analyzed, at all concentrations, showed antioxidant activity. T. capitatus and T. zygis EOs were the most active. The IC₅₀ values, for DPPH, ABTS and FIC assays were 0.60, 1.41 and 4.44 mg/mL, respectively, for T. capitatus whilst for T. zygis were 0.90, 2.07 and 4.95 mg/mL, respectively. Regarding antibacterial activity, T. zygis and T. capitatus EOs, in all culture media, had the highest inhibition halos against all tested bacteria. In general terms, the antibacterial activity of all EOs assayed was higher in the medium made with minced beef than with the medium elaborated with cooked ham or dry-cured sausage. Full article

Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences (p < 0.05) were also observed in the volatile composition and chromatic characteristics suggesting different production technologies. A first list of sensory attributes was obtained for this beverage. Therefore, further research must be done in order to characterize this spirit drink, which has gained market value. Full article

Marine-based food supplements can improve human nutrition. In an effort to modulate glycaemic response and enhance nutritional aspects, marine-derived algal food rich in astaxanthin was used in the formulation of a model food (wholemeal cookie). Astaxanthin substitution of cookies made from three flours (wheat, barley and oat) demonstrated a significant reduction in the rate of glucose released during in vitro digestion together with an increase in the total phenolic content (TPC) and antioxidant capacity of the food. The significantly (p < 0.005) lower free glucose release was observed from cookies with 15% astaxanthin, followed by 10% and then 5% astaxanthin in comparison with control cookies of each flour. Total phenolic content, DPPH radical scavenging and Oxygen Radical Absorbance Capacity (ORAC) value also notably increased with increase in astaxanthin content. The results evidence the potential use of microalgae to enhance the bioactive compounds and lower the glycaemic response of wholemeal flour cookie. Full article

Tomatoes are one of the most nutritionally and economically important crops in New Zealand and around the world. Tomatoes require large amounts of water to grow well and are adversely affected by drought stress. However, few studies have evaluated the physicochemical characteristics of commercial tomatoes grown under water stress conditions. Four tomato cultivars (Incas, Marmande, Scoresby Dwarf, and Window Box Red) were grown in a greenhouse under well-watered and drought stress conditions and the tomatoes were harvested when ripe. The physicochemical properties and antioxidant contents of the fruits were compared. There were significant differences between cultivars in quality characteristics—such as dry matter, total soluble solids, and pH parameters—but there were no differences in the quality characteristics between the two treatments of the fruits (p > 0.05); however, there were significant differences (p < 0.05) in the antioxidant compositions (lycopene, total phenolics, and flavonoids) and antioxidant activities (DPPH and ABTS) of the fruits of both cultivars and treatments. Overall, these results indicated that tomatoes increased their bioactive compounds without changing any quality characteristics when exposed to water stress conditions. Full article