Structure, controlled release mechanisms and health benefits of pectins as an encapsulation material for bioactive food components.

Encapsulation of food and feed ingredients is commonly applied to avoid the loss of functionality of bioactive food ingredients. Components that are encapsulated are usually sensitive to light, pH, oxygen or highly volatile. Also, encapsulation is also applied for ingredients that might influence taste. Many polymers from natural sources have been tested for encapsulation of foods. In the past few years, pectins have been proposed as emerging broadly applicable encapsulation materials. The reasons are that pectins are versatile and inexpensive, can be tailored to meet specific demands and provide health benefits. Emerging new insight into the chemical structure and related health benefits of pectins opens new avenues to use pectins in food and feed. To provide insight into their application potential, we review the current knowledge on the structural features of different pectins, their production and tailoring process for use in microencapsulation and gelation, and the impact of the pectin structure on health benefits and release properties in the gut, as well as processing technologies for pectin-based encapsulation systems with tailor-made functionalities. This is reviewed in view of application of pectins for microencapsulation of different sensitive food components. Although some critical factors such as tuning of controlled release of cargo in the intestine and the impact of the pectin production process on the molecular structure of pectin still need more study, current insight is that pectins provide many advantages for encapsulation of bioactive food and feed ingredients and are cost-effective.

Bile acid binding capacity of fish protein hydrolysates from discard species of the West Mediterranean Sea.

Fish protein hydrolysates (FPH), produced from the six main discard species from the West Mediterranean Sea (sardine, horse mackerel, axillary seabream, bogue, small-spotted catshark and blue whiting) were tested for their bile acid binding capacity. This capacity is directly linked to the ability to inhibit bile reabsorption in the ileum and therefore to lower cholesterol levels in the bloodstream. From each species, FPH were obtained by three different enzymatic treatments employing two serine endoproteases (subtilisin and trypsin) sequentially or in combination. The results show statistically significant differences among the fish species, attaining interesting average values of bile acid binding capacity for blue whiting (27.32% relative to cholestyramine on an equal protein basis) and horse mackerel (27.42% relative to cholestyramine on an equal protein basis). The enzymatic treatments did not significantly affect the ability of a given species to bind bile acids. These results are similar to other protein sources, such as soy protein or casein, of proven hypocholesterolemic effect. It can be concluded that fish protein hydrolysates from these discard species are suitable as ingredients in the formulation of cholesterol-lowering supplements.

Production of resistant starch by enzymatic debranching in legume flours.

Resistant starch (RS) was produced by enzymatic hydrolysis of flours from five different legumes: lentil, chickpea, faba bean, kidney bean and red kidney bean. Each legume was firstly treated thermally, then hydrolyzed with pullulanase for 24h at 50°C and pH 5 and lyophilized. At the end of each hydrolysis reaction, the RS amount ranged from 4.7% for red kidney beans to 7.5% for chickpeas. With respect to the curves of RS against hydrolysis time, a linear increase was observed initially and a plateau was generally achieved by the end of reaction. These curves were successfully modeled by a kinetic equation including three parameters: initial RS, RS at long operation time and a kinetic constant (k). Furthermore, the relative increase in hydrolysis, calculated using the kinetic parameters, was successfully correlated to the percentage of amylose.