New Smoothie Products Based on Pumpkin, Banana, and Purple Carrot as a Source of Bioactive Compounds.

Smoothies are fruit- and/or vegetable-based products in form of beverages that are typically semi-liquid, thick in consistency, and mainly consist of purees and juices. Other ingredients, such as yogurt, milk, ice cream, sugar, honey, or simply water may also be added. The present study aimed to elaborate smoothie products based on bananas, pumpkins, and purple carrots. These fruits and vegetables were chosen due to their high bioactive compounds content, potential health benefits, and availability to industry. Five smoothie formulations were produced and analyzed for pH, soluble solids, total phenolic content, anthocyanins, carotenoids, vitamin C, antioxidant activity, instrumental color, and sensory features. From the analysis, the result showed that the obtained smoothies were a good source of total phenolic content (39.1 to 55.9 mg/100 g) and anthocyanin (7.1 to 11.1 mg cyanidin-3-glucoside/100 g), and that they possessed high antioxidant activity (4.3 to 6.2 µM Trolox/g). From sensory evaluation, all the produced smoothies were desirable, but the formulations with banana were scored higher compared to the pumpkin. In conclusion, smoothies composed of pumpkin, banana, and purple carrot can be a good new food product that incorporates nutritional compounds into the human diet.

Consumption of a smoothie or cereal-based breakfast: impact on thirst, hunger, appetite and subsequent dietary intake.

Smoothies are a popular breakfast option. However, liquids may evoke weaker satiation than nutritionally comparable semi-solid and solid foods. This study examined consumption of cereal and milk (CM) or a nutritionally comparable fruit smoothie (FS) for breakfast on subsequent dietary behaviours, in a controlled laboratory setting. Twenty-five participants (age 25 ± 6 y) completed three trials, receiving either CM or FS for breakfast. Afterwards, participants remained isolated for 4 h with ad libitum access to foods/beverages. A repeat trial (CM or FS) allowed exploration of normal variability. Post-breakfast energy intake (EI) (CM = 1465(2436) vs. FS = 1787(3190) kJ, Median (IQR), p = 0.099), time to intake of next food/fluid (meal latency) (CM = 146(97) vs. FS = 180(100) min, p = 0.127), and subjective hunger, desire to eat, fullness and thirst ratings were similar between conditions (p's > 0.05). The mean coefficient of variation for EI and meal latency were 41% and 21%, respectively. Consumption of a FS does not negatively impact acute EI and meal latency.

Thermosonication parameter effects on physicochemical changes, microbial and enzymatic inactivation of fruit smoothie.

With the aim of developing a fruit-based beverage in products which are severely damaged by heat, a high-intensity ultrasound treatment combined with moderate heat treatment (called thermosonication) was applied. A fruit smoothie (mango, jackfruit and rice milk) was thermosonicated applying a Box-Benhken model with amplitude (70, 77.5 or 85%), time (15, 20 or 25 min) and temperature (40, 47.5 or 55 °C) as independent variables. From the obtained samples, microbiological (aerobic mesophilic and Enterobacteriaceae), physicochemical (pH, soluble solids and cloud index) and enzymatic analysis (polyphenol oxidase and pectin methylesterase) were carried out. Aerobic mesophiles and Enterobacteria inactivation in thermosonicated samples were 4.55 Log CFU/mL and 3.85 Log CFU/mL, respectively in most of the treatments applied, being influenced by linear terms of amplitude and temperature (p < 0.001). The cloud index was influenced by time term (p < 0.0001); meanwhile, interaction of amplitude * temperature (p < 0.01) and quadratic of time presented significant effect (p < 0.001) on polyphenol oxidase activity. Further, amplitude term had a significant effect (p < 0.001) on the decrease on pectin methylesterase enzymatic activity. The optimal process condition was 77.5% amplitude, 20 min and 47.5 °C. Thermosonication probed to be effective to control both enzymatic activities in treatments with high amplitudes combined with moderated temperature treatments. Based on this, the use of thermosonication is a viable alternative for fruit-based beverage preservation, that may employ perishable regional natural products offering them an added value.

Glycaemic index, glycaemic load and dietary fibre characteristics of two commercially available fruit smoothies.

In light of the updated Eatwell Guide and the corresponding change in the consumption of fruit smoothies, the aim of this study was to measure the glycaemic index and load of two commercial fruit smoothies and to investigate the retention of dietary fibre following production. In vitro analysis was performed to identify fibre material (cellulose and pectins) using calcofluor staining and immunocytochemical labelling. A repeated measures cross-over study was conducted (n 10) to determine the glycaemic index (GI) and glycaemic load (GL) of the smoothies. Results showed that dietary fibre was still present in the smoothies after processing (16.9-17.5% cellular material by dry weight). The GI was low for both smoothies (39 and 36), whereas the GL was medium and borderline-low, respectively (11.4 and 9.7). The retention of fibre in these smoothies may have a potential positive effect on glycaemic response and may contribute to daily fibre requirements.

The influence of a fruit smoothie or cereal and milk breakfast on subsequent dietary intake: a pilot study.

Smoothies are popular breakfast foods. This study examined the effect of consuming Cereal & Milk (CM) or a nutritionally-comparable Fruit Smoothie (FS) for breakfast on daily energy intake (EI) in free-living adults and the extent to which individuals compensated for calories ingested in a High Energy Fruit Smoothie (HE). Ten participants (28.4 ± 2.2y; 23.3 ± 1.0 kg·m -2, Mean ± SEM) attended the laboratory on 3 consecutive days per week for 3 weeks. Each week, they received a CM, FS or HE breakfast, then recorded all food/beverages consumed across the remainder of the day. The CM and FS were energy-matched to participants' usual breakfast (1675 ± 283 kJ), while the HE contained an additional 100 kJ·kg-1 of maltodextrin (3019 ± 335 kJ). Mean 3-day EI was similar on CM and FS (7894 ± 547 vs. 7570 ± 463 kJ, p > .05), but elevated on HE (8861 ± 726 kJ, p = .012). Thus, individuals who substitute CM for a FS breakfast should be mindful that energy-dense beverages may result in increased daily EI.

Microwave flow and conventional heating effects on the physicochemical properties, bioactive compounds and enzymatic activity of tomato puree.

BACKGROUND: Thermal processing causes a number of undesirable changes in physicochemical and bioactive properties of tomato products. Microwave (MW) technology is an emergent thermal industrial process that offers a rapid and uniform heating, high energy efficiency and high overall quality of the final product. The main quality changes of tomato puree after pasteurization at 96 ± 2 °C for 35 s, provided by a semi-industrial continuous microwave oven (MWP) under different doses (low power/long time to high power/short time) or by conventional method (CP) were studied. RESULTS: All heat treatments reduced colour quality, total antioxidant capacity and vitamin C, with a greater reduction in CP than in MWP. On the other hand, use of an MWP, in particular high power/short time (1900 W/180 s, 2700 W/160 s and 3150 W/150 s) enhanced the viscosity and lycopene extraction and decreased the enzyme residual activity better than with CP samples. For tomato puree, polygalacturonase was the more thermo-resistant enzyme, and could be used as an indicator of pasteurization efficiency. CONCLUSION: MWP was an excellent pasteurization technique that provided tomato puree with improved nutritional quality, reducing process times compared to the standard pasteurization process. © 2016 Society of Chemical Industry.

Stabilization of red fruit-based smoothies by high-pressure processing. Part A. Effects on microbial growth, enzyme activity, antioxidant capacity and physical stability.

BACKGROUND: Non-thermal pasteurization by high-pressure processing (HPP) is increasingly replacing thermal processing (TP) to maintain the properties of fresh fruit products. However, most of the research on HPP-fruit products only partially addresses fruit-pressure interaction, which limits its practical interest. The objective of this study was to assess the use of a mild HPP treatment to stabilize red fruit-based smoothies (microbial, enzymatic, oxidative and physical stability). RESULTS: HPP (350 MPa/10 °C/5 min) was slightly less effective than TP (85 °C/7 min) in inactivating microbes (mesophilic and psychrophilic bacteria, coliforms, yeasts and moulds) in smoothies kept at 4 °C for up to 28 days. The main limitation of using HPP was its low efficacy in inactivating oxidative (polyphenol oxidase and peroxidase) and hydrolytic (pectin methyl esterase) enzymes. Data on antioxidant status, colour parameters, browning index, transmittance, turbidity and viscosity confirmed that the HPP-smoothies have a greater tendency towards oxidation and clarification, which might lead to undesirable sensory and nutritional changes (see Part B). CONCLUSION: The microbial quality of smoothies was adequately controlled by mild HPP treatment without affecting their physical-chemical characteristics; however, oxidative and hydrolytic enzymes are highly pressure-resistant, which suggests that additional strategies should be used to stabilize smoothies. © 2016 Society of Chemical Industry.

Stabilisation of red fruit-based smoothies by high-pressure processing. Part II: effects on sensory quality and selected nutrients.

BACKGROUND: Non-thermal pasteurisation by high-pressure processing (HPP) is increasingly replacing thermal processing (TP) to maintain the properties of fresh fruit products. The resulting products need to be validated from a sensory and nutritional standpoint. The objective was to assess a mild HPP treatment to stabilise red fruit-based smoothies in a wide (sensory quality and major nutrients) study. RESULTS: HPP (350 MPa/ 10 °C/ 5 min) provided 'fresh-like' smoothies, free of cooked-fruit flavours, for at least 14 days at 4 °C, although their sensory stability was low compared with the TP-smoothies (85 °C/ 7 min). In HPP-smoothies, the loss of fresh fruit flavour and reduced sliminess were the clearest signs of sensory deterioration during storage. Furthermore, HPP permitted the higher initial retention of vitamin C, although this vitamin and, to a lesser extent, total phenols, had a higher degradation rate during storage. The content of sugar present was not affected by either processing treatment. CONCLUSION: Mild HPP treatment did not alter the sensory and nutritional properties of smoothies. The sensory and nutritional losses during storage were less than might be expected, probably due to the high antioxidant content and the natural turbidity provided by red fruits. © 2016 Society of Chemical Industry.

Development of high protein, high fiber smoothie as a grab-and-go breakfast option using response surface methodology.

The current work aimed to formulate smoothie by optimizing varying levels of soy protein isolate (1.5-2.5% w/w), sucralose (150-190 ppm) and pectin (0.3-0.5% w/w) along with milk, legume (chickpea), vegetable (carrot), fruit (mango), honey and trisodium citrate by response surface methodology on the basis of sensory (color and appearance, flavor, consistency, sweetness and overall acceptability) and physical (expressible serum and viscosity) responses. Soy protein isolate and pectin levels influenced color and appearance, flavor, consistency and overall acceptability significantly. Soy protein isolate and pectin showed a positive correlation with viscosity of smoothie with reduced expressible serum. Smoothie was optimized with 1.8% (w/w) soy protein isolate, 166.8 ppm sucralose, and 0.5% (w/w) pectin with acceptable quality. One serving (325 ml) of optimized smoothie provides approximately 23% protein, 27% dietary fiber of the recommended daily values and provides approximately 74 kcal per 100 ml of smoothie, which renders smoothie as a high protein, high fiber, grab-and-go breakfast option.

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.

Essential Oil Nanoemulsions-A New Strategy to Extend the Shelf Life of Smoothies.

Over the years, consumer awareness of proper, healthy eating has increased significantly, but the consumption of fruits and vegetables remains too low. Smoothie drinks offer a convenient way to supplement daily diets with servings of fruits and vegetables. These ready-to-eat beverages retain the nutritional benefits of the raw ingredients from which they are made. Furthermore, they cater to the growing demand for quick and nutritious meal options. To meet consumer expectations, current trends in the food market are shifting towards natural, high-quality products with minimal processing and extended shelf life. Food manufacturers are increasingly aiming to reduce or eliminate synthetic preservatives, replacing them with plant-based alternatives. Plant-based preservatives are particularly appealing to consumers, who often view them as natural and organic substitutes for conventional preservatives. Essential oils, known for their antibacterial and antifungal properties, are effective against the microorganisms and fungi present in fruit and vegetable smoothies. However, the strong taste and aroma of essential oils can be a significant drawback, as the concentrations needed for microbiological stability are often unpalatable to consumers. Encapsulation of essential oils in nanoemulsions offers a promising and effective solution to these challenges, allowing for their use in food production without compromising sensory qualities.

Effect of dual modifications with ultrasonication and succinylation on Cicer arietinum protein-iron complexes: Characterization, digestibility, in-vitro cellular mineral uptake and preparation of fortified smoothie.

The research aimed to evaluate the effect of ultrasonication and succinylation on the functional, iron binding, physiochemical, and cellular mineral uptake efficacy of chickpea protein concentrate. Succinylation resulted in significant improvements in the water-holding capacity (WHC) (25.47 %), oil-holding capacity (OHC) (31.38 %), and solubility (5.80 %) of the chickpea protein-iron complex. Mineral bioavailability significantly increased by 4.41 %, and there was a significant increase in cellular mineral uptake (64.64 %), retention (36.68 %), and transport (27.96 %). The ferritin content of the succinylated chickpea protein-iron complex showed a substantial increase of 66.31%. Furthermore, the dual modification approach combining ultrasonication and succinylation reduced the particle size of the protein-iron complex with a substantial reduction of 83.25 %. It also resulted in a significant enhancement of 51.5 % in the SH (sulfhydryl) content and 48.92 % in the surface hydrophobicity. Mineral bioavailability and cellular mineral uptake, retention, and transport were further enhanced through dual modification. In terms of application, the addition of single and dual-modified chickpea protein-iron complex to a fruit-based smoothie demonstrated positive acceptance in sensory attributes. Overall, the combined approach of succinylation and ultrasonication to the chickpea protein-iron complex shows a promising strategy for enhancing the physiochemical and techno-functional characteristics, cellular mineral uptake, and the development of vegan food products.

CO2-moderate-pressure enhances phytonutrients and prolongs shelf-life of flowable smoothie formulated from quadrable functional vegetables.

The effect of non-thermal (HPP and semi-HPP-CO2) and thermal (flash pasteurization, FP) treatments on phytonutrients of flowable smoothie prepared from quadrable vegetable blends (FQVS) was investigated using multidimensional methods. First, FQVS gained an acceptability sensorial index (85.7%) compared with other formulas. FQVS/semi-HPP-CO2 showed a greater microbial stability during storage (0-30 d) compared to HPP and FP. Fructose and glucose highly declined than sucrose in all smoothies, where semi-HPP-CO2 steadily declined this reduction during storage. LC/MS-MS analysis showed that semi-HPP-CO2 preserved most of FQVS's phytonutrients and their antioxidant effects measured by ORAC and oxidative enzymes inhibition assays. Semi-HPP-CO2 acquired the lowest apparent viscosity among different FQVS smoothies, showing its post-processing flowability behavior. Most importantly, semi-HPP-CO2 predicted a reduced power consumption for HPP and reduced the gas emission. In conclusion, blending different vegetables assisted with semi-HPP-CO2 could be a novel approach to produce storage-stable smoothies with adequate amounts of phytonutrients and sensorial scores.

Exploration of Calocybe indica mushroom phenolic acid-kidney bean protein complex: Functional properties, amino acid profiles, in-vitro digestibility, and application in vegan product development.

The study evaluates the interaction between Calocybe indica mushroom polyphenols (phenolic acid) and kidney bean protein (KBPM), aiming to enhance vegan food quality. The mushrooms exhibited a carbohydrate content of 3.65%, an antioxidant activity of 55.04 ± 0.17%, and a phenolic content of 4.86 mg GAE/g. Caffeic and cinnamic acids were identified through high-pressure liquid chromatography. Various concentrations of KBPM were tested at phenolic acid concentrations of 0.025, 0.050, 0.1, 0.2, 0.4, 0.8, and 1%, among these, KBPM 0.2 demonstrated the highest binding efficiency of 99.40 ± 0.05%. Notably, this complex improved the protein's functional properties, such as solubility by 11.43%, water and oil holding capacities by 10.62% and 22.04%, and emulsion capacity and stability by 3.69% and 5.83%, respectively, compared to the native protein. The protein-phenolic acid complex also enhanced thermal stability, surface charge, amino acid content, and reduced particle size compared to native protein. These enhancements also improved protein digestibility and sensory attributes in a fruit-based smoothie.

Diabetes-Specific Complete Smoothie Formulas Improve Postprandial Glycemic Response in Obese Type 2 Diabetic Individuals: A Randomized Crossover Trial.

This study aimed to compare newly developed diabetes-specific complete smoothie formulas with a standard diabetes-specific nutritional formula (DSNF) regarding their effects on glucose homeostasis, insulin levels, and lipid metabolism in obese type 2 diabetes (T2DM) patients. We conducted a randomized, double-blind, crossover study with 41 obese T2DM participants to compare two developed diabetes-specific complete smoothie formulas, a soy-based regular smoothie (SM) and a smoothie with modified carbohydrate content (SMMC), with the standard DSNF, Glucerna. Glycemic and insulin responses were assessed after the participants randomly consumed 300 kilocalories of each formulation on three separate days with a 7-day gap between. Postprandial effects on glycemic control, insulin levels, and lipid metabolism were measured. SMMC resulted in a significantly lower glucose area under the curve (AUC0-240) compared to Glucerna and SM (p < 0.05 for both). Insulin AUC0-240 after SMMC was significantly lower than that after SM and Glucerna (p < 0.05). During the diets, the suppression of NEFA was more augmented on SM, resulting in a less total AUC0-240 of NEFA compared to the SMMC diet (p < 0.05). C-peptide AUC0-240 after SMMC was significantly lower than that after Glucerna (p < 0.001). Conversely, glucagon AUC0-240 after SMMC was significantly higher than that after SM and Glucerna (p < 0.05). These results highlight SMMC as the better insulin-sensitive formula, potentially achieved through increased insulin secretion or a direct reduction in glucose absorption. The unique composition of carbohydrates, amino acids, and fats from natural ingredients in the smoothies may contribute to these positive effects, making them promising functional foods for managing diabetes and obesity.

Evidence of increases of phytol and chlorophyllide by enzymatic dephytylation of chlorophylls in smoothie made from spinach leaves.

Phytol is a diterpene alcohol found abundantly in nature as the phytyl side chain of chlorophylls. Free form of phytol and its metabolites have been attracting attention because they have a potential to improve the lipid and glucose metabolism. On the other hand, phytol is unfavorable for those who suffering from Refsum's disease. However, there is little information on the phytol contents in leafy vegetables rich in chlorophylls. This study indicated that raw spinach leaves contain phytol of 0.4-1.5 mg/100 g fresh weight. Furthermore, crude enzyme extracted from the leaves showed the enzyme activities involved in dephytylation of chlorophyll derivatives and they were high at mild alkaline pH and around 45°C, and lowered at 55°C or above. Under the optimum pH and temperature for such enzymes determined in the model reaction using the crude enzyme, phytol content in the smoothie made from raw spinach leaves increased with an increase of chlorophyllide, another reaction product. Comparison between the increased amounts of phytol and chlorophyllide showed that the enzymatic dephytylation of chlorophylls was critically responsible for the increase of phytol in the smoothie. PRACTICAL APPLICATION: Phytol, which is released by the enzymes related to chlorophyll metabolism in plants, has been investigated because of its potential abilities to improve the lipid metabolism and blood glucose level. In contrast to such health benefits, they are known to be toxic for patients suffering from Refsum's disease. This research for the first time reports the phytol content in raw spinach leaves and that phytol can be increased in the smoothie made from spinach leaves by the action of endogenous enzymes on chlorophyll derivatives under a certain condition. These results help control phytol content in the smoothies.

The Effects of Dairy and Plant-Based Liquid Components on Lutein Liberation in Spinach Smoothies.

Lutein is a dietary lipophilic compound with anti-inflammatory properties. We have previously shown that dairy fat can improve the lutein content in spinach smoothies. It is, however, unclear whether fat concentrations and fermentation status in dairy products affect lutein liberation in smoothies. Moreover, plant-based milks vary in fat, protein, and fiber content which may affect lutein dissolution. This study aimed to provide translatable information to consumers by comparing lutein liberation in spinach smoothies made with different dairy or plant-based liquids in domestic settings. The smoothies were digested in vitro, and liberated lutein was measured by high-performance liquid chromatography (HPLC). High-fat and medium-fat cow's milk, as well as coconut milk with and without additives, were found to significantly improve lutein liberation by 36%, 30%, 25%, and 42%, respectively, compared to blending spinach with water alone. Adjustment models suggested that the effects of cow's milk and coconut milk were derived from fat and protein, respectively. On the other hand, soymilk with and without additives showed significantly reduced lutein liberation by 40% and 61%, respectively. To summarize, only 4 out of 14 tested liquids increased lutein liberation in spinach smoothies. The results highlight the importance of testing food companions for lipophilic active ingredients.

Fermented Whey Ewe's Milk-Based Fruit Smoothies: Bio-Recycling and Enrichment of Phenolic Compounds and Improvement of Protein Digestibility and Antioxidant Activity.

This study aimed to recycle whey milk by-products (protein source) in fruit smoothies (phenolic compounds source) through started-assisted fermentation and delivering sustainable and healthy food formulations capable of providing nutrients that are unavailable due to an unbalanced diet or incorrect eating habits. Five lactic acid bacteria strains were selected as best starters for smoothie production based on the complementarity of pro-technological (kinetics of growth and acidification) traits, exopolysaccharides and phenolics release, and antioxidant activity enhancement. Compared to raw whey milk-based fruit smoothies (Raw_WFS), fermentation led to distinct profiles of sugars (glucose, fructose, mannitol, and sucrose), organic acids (lactic acid and acetic acid), ascorbic acid, phenolic compounds (gallic acid, 3-hydroxybenzoic acid, chlorogenic acid, hydrocaffeic acid, quercetin, epicatechin, procyanidin B2, and ellagic acid) and especially anthocyanins (cyanidin, delphinidin, malvidin, peonidin, petunidin 3-glucoside). Protein and phenolics interaction enhanced the release of anthocyanins, notably under the action of Lactiplantibacillus plantarum. The same bacterial strains outperformed other species in terms of protein digestibility and quality. With variations among starters culture, bio-converted metabolites were most likely responsible for the increase antioxidant scavenging capacity (DPPH, ABTS, and lipid peroxidation) and the modifications in organoleptic properties (aroma and flavor).

Postprandial Glycemic Response to Whole Fruit versus Blended Fruit in Healthy, Young Adults.

While increased intake of dietary fiber is known to reduce postprandial glycemic response, it is less understood whether the disruption of dietary fiber, in a blender, alters the postprandial glycemic response. We compared the postprandial glycemic response in 20 young, healthy college students (12 female, 8 male) after consuming whole fruit vs. blended fruit. The fruit included gala apple, with the seeds removed, and blackberries. We used a repeated measures two-way ANOVA with fruit treatment as the within-subject variable, sex as the between-subjects factor, and glucose maximum, glucose incremental area under the curve (iAUC), and 60 min glucose as dependent variables. Glucose maximum and glucose iAUC were significantly lower (p < 0.05) in blended fruit compared to whole fruit and 60 min glucose was marginally significantly lower (p = 0.057) in blended fruit compared to whole fruit. Sex was not a significant main effect and sex*treatment was not a significant interaction for any of the dependent variables. We hypothesize that a reduced glycemic response in blended apple and blackberries compared to whole apple and blackberries might be associated with the release of dietary fiber and nutritive components from ground blackberry seeds.

Characterization of Antibiotic Resistant Coliform Bacteria and Resistance Genes Isolated from Samples of Smoothie Drinks and Raw Milk.

Raw foodstuffs have been marked as a healthier alternative in the context of nutrient content and are becoming more popular with consumers. Thermally untreated foods may represent a microbiological risk connected with the possible presence of antimicrobial resistance. The aim of this study was to prove that popular raw food beverages such as smoothies and raw milk may be a source of antibiotic-resistant coliform bacteria and resistant genes. The majority of antibiotic-resistant isolates (110) were identified as Enterobacter spp., Escherichia coli, and species of Klebsiella spp., predominantly ß-lactam and chloramphenicol resistant. Multidrug resistance has been registered in one-third of resistants. Overproduction of efflux pumps was clarified in 8 different bacteria. The majority of resistant isolates were strong biofilm producers. Antibiotic resistance gene blaOXA was detected in 25% of isolates, especially in E. coli. Resistance genes blaTEM and blaSHV were detected in 19% and 14%, respectively. This is the first study to point out that popular raw drinks such as smoothies or raw milk, besides their nutrient benefits, could represent a reservoir of antibiotic-resistant bacteria as well as antibiotic resistance genes. According to this, raw drinks could contribute to the dissemination of antibiotic resistance in the human gastrointestinal tract and environment.