Improved freeze drying efficiency by ice nucleation proteins with ice morphology modification.

This study aims to use ice nucleation proteins (INPs) as a novel approach to improve the efficiency of freeze drying process and investigate the related mechanism of ice morphology. Our results show that INPs can significantly improve freeze drying efficiency with increased primary drying rate under the increase of INP concentration from 0 to 10-2mg/mL. Moreover, such improvement was more significant at higher subzero freezing temperatures with the addition of INPs, when the control samples were unable to freeze. Those improvements further lead to reduced total drying time, which suggests an estimated total energy saving of 28.5% by INPs. Our ice morphology results indicate the ability of INPs to alter ice morphology with lamellar ice structure and larger crystal size, which both show linear relationships with primary drying rate. The results further suggest that these ice morphology characteristics induced by INPs are very likely to facilitate the water vapor flow and improve the sublimation rate. Additionally, the increase of freeze drying efficiency can also be achieved by INPs in other food systems like coffee and milk with elevated primary drying rate. The results of this study suggest great potential of using INPs to improve the efficiency of freeze drying process for a wide range of food products and other related applications. This study also provides new insights into the relationship between process efficiency and ice morphology.

Extruded rice fortified with micronized ground ferric pyrophosphate reduces iron deficiency in Indian schoolchildren: a double-blind randomized controlled trial.

BACKGROUND: Iron fortification of rice could be an effective strategy for reducing iron deficiency anemia in South Asia. OBJECTIVE: We aimed to determine whether extruded rice grains fortified with micronized ground ferric pyrophosphate (MGFP) would increase body iron stores in children. DESIGN: In a double-blind, 7-mo, school-based feeding trial in Bangalore, India, iron-depleted, 6-13-y-old children (n = 184) were randomly assigned to receive either a rice-based lunch meal fortified with 20 mg Fe as MGFP or an identical but unfortified control meal. The meals were consumed under direct supervision, and daily leftovers were weighed. All children were dewormed at baseline and at 3.5 mo. Iron status and hemoglobin were measured at baseline, 3.5 mo, and 7 mo. RESULTS: At baseline, the prevalences of iron deficiency and iron deficiency anemia in the total sample were 78% and 29%, respectively. After 7 mo of feeding, there was a significant increase in body iron stores in both study groups (P < 0.001), with a greater increase in the iron group than in the control group (P < 0.05). There was a significant time x treatment interaction for iron deficiency, which fell from 78% to 25% in the dewormed iron group and from 79% to 49% in the dewormed control group. Iron deficiency anemia decreased from 30% to 15% (NS) in the iron group but remained virtually unchanged in the control group (28% and 27%). In sensory tests, the MGFP-fortified rice (fortified at 3 and 5 mg Fe/100 g) was indistinguishable from natural rice, in both cooked and uncooked form. CONCLUSIONS: Extruded rice fortified with MGFP has excellent sensory characteristics. Fed in a school lunch meal, it increases iron stores and reduces the prevalence of iron deficiency in Indian children.