No abstract

Nixtamalization is the process of steeping dried corn in hot water with calcium hydroxide (lime) with subsequent removal of all or most of the pericarp through washing. The resulting product is called nixtamal. Approximately 60% of corn tortillas in Mexico are produced from nixtamal, with the remainder prepared from nixtamalized corn flour. Nixtamal was fortified with micronutrient premix containing iron, zinc, folic acid, niacin, riboflavin, and thiamin. Premix composition followed a proposed Mexican regulation for corn flour fortification, adjusted for moisture. Effects of premix on masa adhesiveness, hardness, and pH, as well as tortilla sensory properties, stretchability, rollability, and color were measured. Micronutrient levels were tested in the dry corn, nixtamal, masa, and tortillas. There were no significant differences in masa texture or pH, tortilla rollability, or consumer acceptance of tortillas when comparing unfortified control and fortified treatments. Added thiamin was almost entirely degraded during processing. Folic acid and riboflavin decreased 26 and 45%, respectively, through the masa‐tortilla manufacturing process. Niacin showed no significant loss. Despite processing losses, fortification resulted in significant nutrient increases compared with control tortillas. Folic acid increased 974%, riboflavin increased 300%, niacin increased 141%, iron increased 156%, and zinc increased 153% in fortified tortillas.

Cereal Chem. 85(4):561-565Iron deficiency anemia is a widespread occurrence. Consequently, iron is commonly added in cereal fortification programs. However, many iron sources cause undesirable sensory changes, especially color changes, in the food being fortified. This study evaluated the effect of different iron sources on CIE L*a*b* color values and sensory color perception in fortified corn tortillas. Corn masa flour was fortified with micronutrient premix containing vitamins, zinc, and one of eight iron compounds. Iron sources included ferrous fumarate (F), ferrous sulfate (S), ferric orthophosphate (OP), ferrous lactate (L), ferrous gluconate (G), ferric pyrophosphate (PP), sodium iron (III)-EDTA, and A-131 electrolytic iron (E), with addition levels adjusted based on bioavailability. Control (Ct) samples were prepared with all micronutrients except iron. All iron-fortified tortillas had lower L* values and were significantly darker than control tortillas. Based on instrumental color values and Mexican regulatory recommendations, five treatments were selected for further testing. A difference-from-control sensory test was conducted comparing PP, E, OP, F, and S with Ct tortillas. Sensory rankings were C t > E = PP > OP > F > S. A-131 electrolytic iron is recommended for fortification of corn tortillas due to minimal effect on color and significantly lower cost than other iron sources evaluated.

The objective of this study was to better understand the effect of butter composition and emulsion structure on growth and survival of Clostridium sporogenes, used as a surrogate for C. botulinum in canned butter. The lack of a thermal process step in commercially available canned butter raises questions of potential safety, because it is hermetically sealed and generally exhibits anaerobic growth conditions, which are optimal for Clostridium botulinum growth. Without thermal processing, low-acid canned foods must have inhibitory factors present to prevent C. botulinum growth. Some potential intrinsic inhibitory factors, or hurdles, within butter include: reduced water activity, acidity in cultured products, elevated salt content, and the micro-droplet nature of the aqueous phase in the butter emulsion. It was hypothesized that a normal, intact butter emulsion would have sufficient hurdles to prevent C. botulinum growth, whereas a broken butter emulsion would result in a coalesced aqueous phase that would allow for C. botulinum growth. Batch-churned butter was inoculated with C. sporogenes; butter samples with varying salt contents (0, 0.8, 1.6, and 2.4% wt/wt NaCl) were prepared and stored in coated steel cans for varying times (1 or 2 wk) and temperatures (22 or 41°C) to determine temperature and emulsion structure effects on C. sporogenes growth. Samples stored at 41°C showed a significant increase in C. sporogenes growth compared with those stored at 22°C. Furthermore, NaCl addition was found to have a significant effect on C. sporogenes growth, with 0.8% NaCl promoting more growth than 0%, but with decreases in growth observed at 1.6 and 2.4%. Uninoculated control plates were also found to have bacterial growth; this growth was attributed to other anaerobic bacteria present within the cream. It was concluded that removal of the hurdle created by the micro-droplet size of the emulsion aqueous phase could result in C. botulinum growth even at elevated salt levels and, therefore, home preparation of canned butter is not advisable. It is also possible that commercially canned butter, if heat abused, could potentially allow for C. botulinum growth and, therefore, consumption is not recommended.

Brown eggs have gradually entered the traditional white-egg markets as a distinctive mode for packaging specialty eggs. A test was conducted at the Brigham Young University Sensory Laboratory (Provo, UT) to understand how consumers view attributes of the brown egg relative to the white egg. The objectives were to see how the consumer viewed properties of eggs by color and to examine the preference for brown color intensity. The 52 panelists were all women who routinely purchased and consumed eggs. Some women (53.8%) consumed eggs twice weekly, and 40.4% purchased them at least every 2 wk. Purchases included specialty eggs (14.6%) consisting of cage-free (50.0%), organic (28.6%), and n-3 enhanced (21.4%) eggs. The panelists preferred white eggs (90.4%). Though brown-shelled eggs did not exceed white eggs in preference, they were perceived positively (white-shelled %:brown-shelled %) as being more nutritious (65:29), having more flavor (27:14) and n-3 content (62:39), having a farm-flock origin (46:44), and being from organically fed hens (56:31) To test the preference for shade of brown eggs, a set of 6 eggs with varying intensities of brown color was evaluated for accepted appearance using a 9-point hedonic scale. The egg color intensities were measured using a Hunter Colorflex spectrophotometer (Hunter Associates Laboratory, Reston, VA) and the CIE system. The lightness (L*) values ranged from 83.2 for the white egg to 63.6 to 46.5 for the brown eggs. A significant (P < 0.05) preference was found for the 2 lighter shades of brown-shelled eggs (L* 63.6 and 57.5). Using the 9-point scale, panelists then compared brown eggs side by side with white eggs. Again, the 2 most light-tinted brown eggs were found most comparable with the white egg in acceptability and better (P < 0.05) than the darker brown eggs. In conclusion, white eggs were preferred over brown eggs; however, brown eggs gained in acceptance but did not exceed white as likely to be more nutritious or flavorful, fresher, organic, and of cage-free origin. Varying color shades in cartoned eggs was equally as acceptable as uniform colored eggs. Panelists preferred the appearance of the light-tinted brown eggs to that of darker brown eggs.