Bioaccessibility and antioxidant capacity of kefir-based smoothies fortified with kale and spinach after in vitro gastrointestinal digestion

The kefir-based smoothies with kale and spinach were designed as a ready-to-drink and innovative functional snack. Microbiological, physicochemical, as well as pre- and postgastrointestinal total antioxidant capacity (TAC; CUPRAC, DPPH, and FRAP) analyses were conducted. It was determined that the kefir-based smoothies with vegetables had higher ash, carbohydrate, and dietary fiber values. Fructose and glucose contents of smoothy with kale were high, while smoothy with spinach included high sucrose and maltose. The microbiology results revealed that kefir-based vegetable smoothies had minimum Lactobacillaceae viability (>log 7 cfu g-1) for the required functional effect after 14-day storage. Moreover, the addition of kale significantly increased (p < .01) the level of initial TAC (CUPRAC, DPPH, and FRAP) and total phenolic content (TPC) values. After in vitro gastric digestion analysis, smoothie with spinach demonstrated higher TAC and TPC values and the control sample had higher TAC and TPC values compared with a predigestion step. It was found that in vitro intestinal DPPH values were higher for the sample with spinach samples, while the sample with kale had the highest FRAP values. It was also found that the bioaccessibility indexes of plain kefir were determined to be the highest in both in vitro gastric and intestinal procedures. The present study provided novel insights into the in vitro digestion properties of kefir fortified with vegetables. Nevertheless, further studies are needed to identify the functional properties of the milk and plant matrices mixture using in vitro and in vivo trials.

Preliminary Characterization of a Spray-Dried Hydrocolloid from a High Andean Algae (Nostoc sphaericum)

The search for new natural sources of hydrocolloids with stabilizing, thickening, and good binding capacity, from raw materials that are environmentally friendly and that contribute to the circular economy is a challenge for the food industry. The aim of the study was the preliminary characterization of a spray-dried hydrocolloid from high Andean algae Nostoc sphaericum. Four ecotypes of algae from Peruvian high Andean lagoons located above 4000 m were considered. The samples were collected in the period March−April 2021 and were subjected to a spray drying process in an aqueous medium. The characterization showed that the dehydrated nostoc ecotypes presented high protein and carbohydrate content, making it a potential material for direct use as a functional food for humans. The spray-dried product presented good stability for its use as a hydrocolloid, with zeta potential values (ζ), around 30 mV, evidencing the presence of -CO-, -OH, -COO-, and -CH groups, characteristic of polysaccharides, representing 40% of total organic carbon on average, giving it low water activity values and particle size at the nanometric level. Major minerals such as Ca (>277 mg/100 g), Mg (>19.7 mg/100 g), and Fe (>7.7 mg/100 g) were reported. Spray-dried nostoc is a hydrocolloid material with high potential for the food industry, with good nutritional content and techno-functional behavior.

Application of High Hydrostatic Pressure in fresh purple smoothie: Microbial inactivation kinetic modelling and qualitative studies

The inactivation kinetics of Listeria monocytogenes during High Hydrostatic Pressure (HHP) treatments was studied in a purple smoothie based of fresh fruit and vegetables. Pressure intensity studied was 300, 350, 400 and 450 MPa. Untreated samples were used as control. Furthermore, the effects on quality attributes (sensory, total soluble solids content, colour, titratable acidity, pH, vitamin C and total phenolics content) were also monitored. Microbial inactivation was modelled as a function of the HHP intensity using the Geeraerd model. Shoulder and tail effects were observed only for the 300 MPa pressure assayed, supporting a multiple hit kinetic inactivation of critical factors. Increasing the HHP intensity resulted in a faster inactivation with tailing. A strong positive correlation was observed between the pressure level and the inactivation rate (k). Hence, a linear model was used to describe the relationship between both variables. Nevertheless, further data are required to confirm this secondary model. Quality was mostly unaffected by the HHP treatments, except for the vitamin C content, which reported reductions of 26 and 21% after 300 and 350 MPa, respectively. In conclusion, HHP can be a viable technology for processing fruit and vegetable-based smoothies to preserve quality and safety. A pressure of 400 MPa is advisable to ensure an efficient microbial inactivation with the best sensory and nutritional quality retention.

UV-B Radiation as Abiotic Elicitor to Enhance Phytochemicals and Development of Red Cabbage Sprouts

Background: The main objective of this study was to evaluate the effect of periodical UV-B illumination during red cabbage germination on morphological development and the phenolics and carotenoid accumulation. Methods: During a sprouting period of 10 days at 20 °C in darkness, seedlings received 5, 10, or 15 kJ m−2 UV-B (T5, T10, and T15) applied in four steps (25% on days 3, 5, 7, and 10). UV untreated sprouts were used as control (CTRL). After 10 days of germination, the sprouts were harvested and stored 10 days at 4 °C as a minimally processed product. Phenolic and carotenoid compounds were analysed 1 h after each UV-B application and on days 0, 4, 7, and 10 during cold storage. Results: The longest hypocotyl length was observed in T10-treated sprouts. The total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) increased during germination following a sigmoidal kinetic, especially in the UV-B-treated samples, which reported a dose-dependent behaviour. In this way, T10-treated sprouts increased the TPC by 40% after 10 days at 4 °C compared to CTRL, while TAC and TFC increased by 35 and 30%, respectively. Carotenoids were enhanced with higher UV-B doses (T15). Conclusions: We found that UV-B stimulated the biosynthesis of bioactive compounds, and a dose of 10 kJ m−2 UV-B, proportionally applied on days 3, 5, 7, and 10 days, is recommended.

Postharvest UV-B and Photoperiod with Blue + Red LEDs as Strategies to Stimulate Carotenogenesis in Bell Peppers

Background: Our objective was to evaluate carotenoid accumulation in bell peppers during shelf life under different light conditions. Methods: Fruit stored for 6 d at 7 °C received a 9 kJ m−2 UV-B treatment, while non-UV-treated were used as control (CTRL). Subsequently, all peppers were disposed for a retail sale period of 4 d at 20 °C with a photoperiod of 14 h under fluorescent light (FL) + 10 h under darkness (D), FL, or blue + red LEDs (BR LED). Results: Total antioxidant capacity (TAC) was increased by the UV-B treatment and the photoperiods supplemented with FL and BR LED, which was directly related to the carotenoid content. In fact, CTRL peppers (225 mg β-carotene kg−1) under FL+BR LED showed an increase of ~33% of 13-cis-β-carotene, ~24% of all-trans-β-carotene, and ~27.5% of 9-cis-β-carotene compared to FL + D and FL + FL. Capsaicinoids showed an increase by ~22%, ~38%, and ~27% in the content of capsanthin, capsanthin laurate, and capsanthin esters, respectively, after the UV-B treatment, which was even enhanced after the LED-supplemented photoperiod by ~18% compared to FL+D. Conclusions: Illumination with BR LEDs + UV-B during the retail sale period nights is recommended to increase the bioactive content of bell peppers via carotenoid accumulation to 270 mg β-carotene kg−1.

Microalgal biomass — a bio-based additive: evaluation of green smoothies during storage

Microalgae biomass addition to food has been studied for its nutritional fortification. The present work investigates the impact of microalgae (Chlorella vulgaris and Dunaliella salina) addition, in terms of quality characteristics, during a 28-day storage at 5°C. As much as 2.5% (w/v) of C. vulgaris and D. salina were separately added to fresh green smoothies (spinach, green apple, and cucumber) as food additive. Without any thermal application during storage at 5°C, the changes in pH, total soluble, solid contents, titratable acidity, microbial loads, phenolic contents, antioxidant activity, and sensory characteristics were determined. The addition of microalgae biomass, either Chlorella or Dunaliella, was found statistically significant, but this addition did not make a significant difference during the 28-day storage. Compared to control samples (at day 0; 163.16 mg GAE/100 g and 2.56 mmol GAE/100 g), Dunaliella biomass affected green smoothie more positively on total phenolic (at day 0; 395.79 mg GAE/100 g) and antioxidant activity (at day 0; 5.54 mmol GAE/100 g), than Chlorella biomass (at day 0; 384.21 mg GAE/100 g and 4.22 mmol GAE/100 g). Also, a shelf-life study on 28-day storage at 5°C found that Dunaliella-added smoothies were more preferred by the panellists, while Chlorella-added samples exhibited off-odour and off-flavour through storage. Smoothie supplementation with 2.5% microalgae biomass caused a decrease in the initial microbial load. Due to this reduction, it can be said that microalgae supplementation as an additive was effective, and microalgae-added samples were shown below the "microbiologically consumable level" throughout the 28-day shelf-life study.

Development and Quality Evaluation of Freeze-Dried Instant Green Smoothie Powder

Fruits and vegetables are healthy food sources which contain nutrients and phytochemicals with health-promoting properties. The production of healthy and more convenient products can be contributed to increase the consumption of fruits and vegetables. In this study, a novel, instant food product which is more nutritive was developed using locally available fruits and green leafy vegetables and the physicochemical, microbial, and sensory qualities of the product were studied. The most acceptable formula for the fresh green smoothie was 28.6% green content with 71.4% fruit content. The developed green smoothie was freeze dried to obtain an instant green smoothie powder. The instant green smoothie powder was analyzed for proximate composition: protein (2.67 ± 0.00), fat (1.96 ± 0.001), moisture (4.82 ± 0.003), ash (1.22 ± 0.000), and fiber (28.57 ± 0.008). This instant powder contained 129.5 ppm vitamin C content and higher amount of minerals such as K (0.98 ± 0.12 mg/g), Ca (1.74 ± 0.03 mg/g), and Fe (0.04 ± 0.004 mg/g). The powder properties revealed that the powder has very good flowability (6.665 ± 2.354) according to the Carr Index and it has low cohesiveness (1.0713 ± 0.0264) according to the Hausner ratio. The solubility (94.71 ± 2.4253) of the powder complied with the SLS (668: 1984). The microbiological analysis revealed that this powder only contains 1 log CFU/ml of total plate count. This instant powder can be introduced as a more convenient and healthy choice for the consumers which has acceptable sensory properties, better microbiological stability, and very good powder properties.

Postharvest LED lighting: effect of red, blue and far red on quality of minimally processed broccoli sprouts

BACKGROUND

The main objective of this study was to evaluate physiological and quality changes of minimally processed broccoli sprouts illuminated during postharvest storage under blue, red and far-red LED lighting as compared to darkness or illumination with fluorescent light, as control treatments.

RESULTS

Morphological and microbiological changes were determined during 15 days at 5 °C. In addition, total antioxidant activity and bioactive compound changes throughout the shelf life were also monitored. Results showed that far-red LED lighting increased hypocotyl and sprout length, decreased microbial growth and improved the total antioxidant and scavenging activities, compared to darkness and fluorescent lighting treatments. However, it did not stimulate the biosynthesis of phenolic acids. In contrast, blue LED light reduced by 50% the total antioxidant capacity of broccoli sprouts compared to far-red treatment, as well as morphological development. In addition, total scavenging activity was increased under far-red LED light compared with the other treatments by 12-10% (darkness and fluorescence) and 33-31% (blue and red LEDs).

CONCLUSIONS

Our results suggest that minimally processed sprouts may benefit from LED lighting during shelf life in terms of quality, although further experiments should be conducted to optimize a proper exposure cycle and intensity aiming for use in the distribution chain. The results also open the way for further development towards the integration of this technology in the food distribution chain.

Revalorized broccoli by-products and mustard improved quality during shelf life of a kale pesto sauce

The effect of revalorized Bimi leaves (B) and/or mustard (M) addition, as supplementary ingredients, to develop an innovative kale (K) pesto sauce was studied. Microbial, physicochemical (color, total soluble solids content -SSC-, pH and titratable acidity -TA-) and sensory quality were studied during 20 days at 5 °C. Bioactive compounds changes (total phenolics, total antioxidant capacity and glucoraphanin contents) were also monitored throughout storage. The high TA and pH changes in the last 6 days of storage were avoided in the K+B pesto when adding mustard, due to the antimicrobial properties of this brassica seed. SSC was increased when B + M were added to the K pesto, which positively masked the kale-typical bitterness. Mustard addition hardly change yellowness of the K pesto, being not detected in the sensory analyses, showing K+B+M pesto the lowest color differences after 20 days of shelf life. The addition of Bimi leaves to the K pesto enhanced its phenolic content while mustard addition did not negatively affect such total antioxidant compounds content. Finally, mustard addition effectively aimed to glucoraphanin conversion to its bioactive products. Conclusively, an innovative kale pesto supplemented with Bimi by-products was hereby developed, being its overall quality well preserved up to 20 days at 5 °C due to the mustard addition.

Challenges and Directions in Zoo and Aquarium Food Presentation Research: A Review

From its foundations in agricultural science, zoo animal nutrition has developed into a biologically informed, evidence-based discipline. However, some facets of nutrition still make use of a more traditional approach, such as the field of zoo presentation. For example, it is common practice to prepare animal diets by chopping them into bite-size chunks, yet there is limited peer-reviewed evidence that explains the benefits and welfare implications of this practice. The chopping and placement of foods can alter desiccation rates, nutrient breakdown, and food contamination, so it is important to evaluate the implications of current practices. Here, the published literature on the behavioral impacts of different food presentation formats (such as clumped and scattered, and chopped and whole) is reviewed, with reference to a range of taxa. The current state of knowledge of the nutritional and microbiological effects of food presentation practices are also reviewed. Relevant research is available on the behavioral effects of some forms of zoo food presentation; however, relatively little research has been conducted on their nutrient composition effects or desiccation rates. Similarly, there are gaps in terms of the species that have been investigated, with a few mammalian taxa dominating the food presentation literature. Future research projects covering social, behavioral, and welfare impacts, and the nutritional and microbiological consequences of food presentation would further evidence-based zoo and aquarium management practices. Similarly, qualitative research surrounding keeper perception of food presentation formats would help to identify challenges and opportunities in this field.

Anti-diabetic, anti-cholinesterase, and antioxidant potential, chemical composition and sensory evaluation of novel sea buckthorn-based smoothies

Sea buckthorn berries fit into the strategy of seeking natural factors in the non-communicable diseases prevention, but their sensory qualities are a challenge for consumers and food industry. The study aimed to evaluate anti-cholinesterase (anti-acetylcholinesterase and -butylcholinesterase), anti-diabetic (anti-α-amylase, -α-glucosidase, -pancreatic lipase) and antioxidant potential (FRAP, ORAC), phenolic compounds (UPLC-PDA-FL), basic chemical composition, and sensory quality of sea buckthorn-based smoothies. Eighteen novel products containing sea buckthorn (25-50%) with other fruits and vegetables were analyzed. Sea buckthorn enriched the smoothies in flavonols (25.46-95.13 mg/100 g), and fruits and vegetables provided phenolic acids and procyanidins. The anti-BuChE effect was higher than anti-AChE, while products with apricot, orange, grape and parsley root were strong inhibitors of carbohydrates digesting enzymes. Lipase inhibition by all smoothies was over 50%. Products with 75% fruits or 50% vegetables were the most sensory attractive. The results will be valuable in designing innovative food with rarely used berries.

Kinetics of the carotenoid concentration degradation of smoothies and their influence on the antioxidant status of the human skin in vivo during 8 weeks of daily consumption

The antioxidant status of the skin shows constant alterations depending on nutrition and other lifestyle factors. Carotenoids can serve as marker substances for the antioxidant status of the epidermis in vivo. The carotenoid concentration of 2 homemade green smoothies and a commercial green smoothie, all containing fruits and vegetables, was assessed by resonance Raman spectroscopy. Furthermore, a pilot study was conducted to investigate changes of the cutaneous carotenoid concentration of 20 healthy volunteers under the daily intake of either a homemade smoothie or the commercial smoothie in vivo using reflectance spectroscopy. We hypothesized that higher carotenoid concentrations in the homemade smoothies compared to those of the commercial one would lead to a faster increase of the cutaneous carotenoid concentration in healthy volunteers. The measurements of the homemade smoothies showed notably higher initial carotenoid concentrations (7.6 ±0.8)*10^-4arbitrary units (a.u.) (smoothie A) and (10.4 ± 0.6)*10^-4 a.u. (smoothie B) compared to the commercial smoothie (5.8 ± 0.2)*10^-4 a.u. Nevertheless, the commercial smoothie showed a higher stability of carotenoids over 24 hours. 8 weeks after daily consumption of the homemade smoothies, volunteers showed an insignificant increase of cutaneous carotenoids from (4.5 ± 0.1)*10^-4 a.u. at baseline to (4.8 ± 0.3)*10^-4 a.u. (means ± standard error of the mean). The volunteers consuming the commercial smoothie showed an insignificant increase of cutaneous carotenoids from (4.3 ± 0.2)*10^-4 a.u. to (4.7 ± 0.2)*10^-4 a.u. after 8 weeks. The observed increase of cutaneous carotenoid concentrations could be classified as a strong tendency. Fresh homemade smoothies can exhibit a higher carotenoid concentration compared to commercial smoothies but need to be consumed immediately after preparation.

Effect of stevia supplementation of kale juice spheres on their quality changes during refrigerated shelf life

BACKGROUND

Kale is a vegetable that contains a high proportion of health-promoting compounds although its consumption as a beverage is very limited due to its bitter flavor. Nonetheless, the bitter flavor of Brassica may be masked by sweetening. The effects were studied of different stevia extracts (CTRL, S0.5 (g L^-1 ), S1.25 and S2.5) added to a kale beverage on the quality of kale juice spheres over a period of 7 days at 5 °C. Kale juice spheres were produced with a double-spherification technique, which allowed hydrogel spheres to be produced with high mechanical resistance.

RESULTS

The addition of the stevia extracts did not affect the physicochemical quality of spheres. In particular, S2.5 spheres showed the least color changes after 7 days. All spheres showed good microbiological quality throughout storage, with loads < 7 log CFU g^-1 , regardless of the stevia concentration. The sulforaphane content of kale spheres was not affected by the stevia supplementation over the 7-day period.

CONCLUSION

The addition of stevia to the kale juice spheres led to a better flavor without altering product quality during refrigerated storage. © 2018 Society of Chemical Industry.

Natural vitamin B12 and fucose supplementation of green smoothies with edible algae and related quality changes during their shelf life

BACKGROUND

Some algae are an excellent sources of vitamin B12, of special interest for vegetarian/vegan consumers, and of fucose to supplement fruit and vegetable beverages such as smoothies. Nevertheless, supplementation of smoothies with algae may lead to possible quality changes during smoothie shelf life that need to be studied. Therefore, the quality changes in fresh green smoothies supplemented (2.2%) with nine edible algae (sea lettuce, kombu, wakame, thongweed, dulse, Irish moss, nori, Spirulina and Chlorella) were studied throughout 24 days at 5 °C.

RESULTS

The initial vitamin C content - 238.7-326.0 mg kg^-1 fresh weight (FW) - of a 200 g portion of any of the smoothies ensured full coverage of its recommended daily intake, and still supplying 50-60% of the recommended intake after 7 days. Chlorella and Spirulina smoothies showed the highest vitamin B12 content (33.3 and 15.3 µg kg^-1 FW, respectively), while brown algae showed fucose content of 141.1-571.3 mg kg^-1 FW. These vitamin B12 and fucose contents were highly maintained during shelf life.

CONCLUSION

The Spirulina supplementation of a 200 g smoothie portion ensured full coverage of the recommended vitamin B12 intake, with lower vitamin C degradation, during a shelf life of 17 days. Furthermore, thongweed and kombu are also considered as excellent fucose sources with similar shelf life. © 2017 Society of Chemical Industry.

Improved quality of a vitamin B12-fortified ‘ready to blend’ fresh-cut mix salad with chitosan

A vitamin B12-fortified (0.25 mg L−1) chitosan (10 g L−1) coating was applied to a ready-to-blend fresh-cut salad including melon, pineapple and carrot, which was stored at 5 ℃ up to nine days. Uncoated samples were used as control while the vitamin B12 effect was compared to non-fortified chitosan-coated samples. Beverages were prepared on blending days 0, 4, 7 and 9 with subsequent storage at 5 ℃ for 0, 24 and 48 h. Physicochemical quality of fresh blended beverages was well preserved throughout storage. The chitosan coating highly reduced epiphytic microflora growth and polyphenoloxidase/peroxidase activities. No relevant variations of total phenolic contents were observed between different fresh blended beverages. However, its total antioxidant capacity reported after blending was lower as storage time of ready-to-blend samples increased. Fortified samples showed a vitamin B12 content of 8.6 µg kg−1 on processing day, ensuring 200 mL of such beverage the recommended daily intake of this vitamin. In conclusion, a ready-to-blend fruit/vegetable mix, fortified with vitamin B12, was developed with a shelf life of nine days at 5 ℃ showing the prepared beverages good quality during subsequent storage for 48 h at 5 ℃.