Smoothies Marketed in Spain: Are They Complying with Labeling Legislation?

The Application of Mulberry Elements into a Novel Form of Easy-to-Prepare Dried Smoothie

The European market offers a variety of functional foods targeted at prediabetic and diabetic patients, with different approaches to reducing postprandial glucose levels. The utilization of white and black mulberry in new products could be an area of interest to many conscious consumers. The study aimed to design a novel form (dried) of easy-to-prepare product by applying nutritious mulberry in various proportions and creating an aesthetically appealing smoothie product with a distinctive taste profile. Such an easy-to-prepare form of smoothie was obtained by utilizing the freeze-drying process, while typical market smoothies are liquid. Sensory evaluations of the fresh, dried, and reconstructed smoothies and their basic characteristics were conducted. Moreover, antiradical tests (with ABTS+• and DPPH•), the phenolic compound profile (HPLC/PDA), and the L*a*b profile were analyzed. The results of the sensory evaluation tests were divided into two groups: Polish and foreign panelists. It was observed that mulberry-licorice drop-based smoothies were preferred fresh. Yet dried and reconstituted capsule-based smoothies were favored overall. Generally, both Polish and foreign panelists preferred lower concentrations of mulberry and licorice extracts (DB) in fresh smoothies, while in dried or reconstructed smoothie form, panelists scored higher (DC) and lower (DB) concentrations quite similarly (favored both concentrations). From the group of identified phenolic compounds, cinnamic acid derivates dominated all analyzed smoothies. Many analyzed types of flavonoids (quercetin, rutin, kaempferol) and naringenin were found in the smoothies. Some differences were noted in the antiradical tests but were only statistically significant for DPPH• scavenging activity, which was higher for the DB1, DB2, and DC1 samples. Generally, even higher addition of licorice and mulberry did not negatively affect panelists’ ratings and the analyzed activities.

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.