Redness generation via Maillard reactions of whey protein isolate (WPI) and ascorbic acid (vitamin C) in spray-dried powders

Optimization of process parameters of refractance window drying for aonla slices and comparison with other drying techniques

BACKROUND

Aonla is as a good source of antioxidants due to its high ascorbic acid and polyphenol contents. However, because of its high acidity and astringent taste, aonla is rarely consumed in its fresh form. As the constituents in aonla are heat sensitive, it is essential to find a suitable drying method for preservation. Therefore, refractance window drying (RWD) of aonla slices was studied as it has the potential of retaining heat-sensitive compounds.

RESULTS

The effect of RWD process variables, namely water temperature (75, 82.5, 90 °C) and slice thickness (2, 4, 6 mm), on different quality parameters of dehydrated aonla was studied. Increasing water temperature resulted in significantly higher ascorbic acid content, titratable acidity and product temperature, while total phenolic content, free radical scavenging activity and moisture content decreased. With the exception of product temperature, higher slice thickness led to an increase in the values of all the parameters. At the optimized processing conditions of 83 °C water temperature and 4 mm slice thickness, the ascorbic acid content, total phenolic content, free radical scavenging activity, titratable acidity and moisture content values were found to be 269.03 mg (100 g)-1, 242.33 mg (100 g)-1, 87.11%, 3.62% and 4% respectively. The aonla slices subjected to RWD also possessed 4-6% higher phytochemical content than osmotically dried and hot-air-dried samples.

CONCLUSION

This research highlights the effectiveness of RWD in preserving heat-sensitive compounds in food like aonla. The RW-dried slices had a smoother and more uniform microstructure compared to osmotically dried and hot-air-dried samples. © 2024 Society of Chemical Industry.

Fortifying jelly foods with microencapsulated anti-anaemic compounds, ferrous gluconate, ascorbic acid and folic acid

Low ferrous iron bioavailability presents a challenge for food fortification programmes. In this study, jelly foods were fortified with spray-dried chitosan microparticles that had been loaded with ferrous gluconate (FeG) and folic acid (FA) to alleviate iron deficiency anaemia and FA deficiency anaemia, respectively. The presence of FA and ascorbic acid (AA) increased the in vitro iron bioavailability of the FeG-AA-FA microparticles up to sixfold. Furthermore, the iron bioavailability of the fortified jelly foods increased more than 5 folds compared to that of the FeG-AA-FA microparticles. The use of lower temperature during the preparation of fortified jelly foods is recommended to avoid the microparticles' decomposition and a Maillard browning reaction. These findings can help food technologists and product developers select formulations with higher ferrous bioavailability to reduce the prevalence of anaemia.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05599-7.

A Literature Review on Maillard Reaction Based on Milk Proteins and Carbohydrates in Food and Pharmaceutical Products: Advantages, Disadvantages, and Avoidance Strategies

Milk has two main components that have high nutritional value—milk protein (casein and whey protein), and lactose. These components are extensively used in various areas, especially in food, i.e., as sweeteners, stabilizers, functional food ingredients, nutritional fortifiers, etc. Non-enzymatic browning refers to a series of chemical reactions between sugars and proteins that make food more appetizing. Non-enzymatic browning reactions include degradation of ascorbic acid, lipid peroxidation, caramel reaction, and the Maillard reaction (MR). The MR, as one of the four non-enzymatic browning reactions, has been well studied and utilized in food fields. Milk protein and lactose, as two main components of milk, have high chemical activities; they are used as reactants to participate in the MR, generating Maillard reaction products (MRPs). The MR involves a condensation reaction between carbonyl groups of various sugars and amino groups of amino acids/proteins. These MRPs have different applications in various areas, including food flavor, food oxidation resistance, drug carriers, etc. This work presents the positive and negative effects of the MR, based on the two main components of milk, used in food and medicine, as well as avoidance approaches to prevent the occurrence of negative effects.

Optimization of the spray drying process for developing cupuassu powder

A central composite design was used to optimize the spray drying process for developing cupuassu (Theobroma grandiflorum) powder. The influence of inlet air temperature (T_inlet) (120-180 °C), feeding rate (F_feed) (3-12 mL/min) and maltodextrin concentration (C_malto) (10-40%) on the properties of moisture, water activity (a_w), hygroscopicity, water solubility index (WSI), ascorbic acid (AA) and total phenolic compounds (TPC) were analyzed using response surface methodology and desirability function. In addition, powder morphology was assessed using scanning electron microscopy. The T_inlet and F_feed parameters significantly influenced the moisture and a_w, while the other responses (hygroscopicity, WSI, AA and TPC) were influenced by the T_inlet and C_malto parameters. The highest C_malto and intermediate T_inlet and F_feed levels showed the best morphological characteristics (particles integrity, spheres shapes and smooth surfaces). The desirability function defined the optimal process conditions as T_inlet = 150 °C, F_feed = 7.5 mL/min and C_malto = 40%.

Transformation between 2-Threityl-thiazolidine-4-carboxylic Acid and Xylose-Cysteine Amadori Rearrangement Product Regulated by pH Adjustment during High-Temperature Instantaneous Dehydration

2-Threityl-thiazolidine-4-carboxylic acid (TTCA) was found to be the predominant product rather than the Amadori rearrangement product (ARP) during the formation of xylose-cysteine-derived (Xyl-Cys-derived) Maillard reaction intermediates (MRIs) through a thermal reaction coupled with vacuum dehydration. To regulate the existence forms of Xyl-Cys-derived MRIs, an effective method carried out by pH adjustment during high-temperature instantaneous dehydration through spray-drying was proposed in this research to promote the conversion from TTCA to ARP. The increased inlet air temperature of spray-drying could properly facilitate the shift of chemical equilibrium between the MRIs and promote the transformation from TTCA to ARP while raising the total yield of TA (TTCA + ARP). The conversion to ARP was increased to 20.83% at 190 °C of hot blast compared to the product without spray-drying (6.03%). The conversion from TTCA to ARP was further facilitated in the pH range of 7.5-9.5. When the pH of the aqueous reactants was adjusted to 9.5, the equilibrium conversion to ARP was improved to 47.23% after spray-drying, which accounted for 59.48% of the TA formation. Accordingly, MRIs with different TTCA/ARP proportions could be selectively obtained by pH adjustment of the stock solution during high-temperature instantaneous dehydration of spray-drying.

Maillard conjugates from spent brewer's yeast by-product as an innovative encapsulating material

Yeast-based by-products are greatly available, have a rich nutritional composition and functional properties. The spent brewer's yeast (SBY) cells after enzymatic hydrolysis may be a sustainable and low-cost alternative as carrier material for encapsulation processes by spray drying. Our work had as main purpose to characterise the hydrolysed SBY cell debris after the Maillard reaction and to study their potential as a microencapsulation wall material. SBY-based Maillard reaction products (MRPs) were used to encapsulate ascorbic acid (AA) by spray drying. The Maillard Reaction was able to improve the solubility of solids and proteins by 15% and promoted brown color development (230% higher Browning Index). SBY-based MRPs resulted in particles of a high encapsulation yield of AA (101.90 ± 5.5%), a moisture content of about 3.4%, water activity of 0.15, hygroscopicity values ranging from 13.8 to 19.3 g_H2O/100 g and a glass transition temperature around 71 °C. The shape and microstructure of the produced particles were confirmed by scanning electron microscopy (MEV), indicating very similar structure for control and AA encapsulated particles. Fourier Transform Infrared Spectroscopy (FT-IR) results confirmed the presence of yeast cell debris in the surface of particles. Ascorbic acid was successfully encapsulated in Maillard conjugates of hydrolyzsd yeast cell debris of Saccharomyces pastorianus and maltodextrin as confirmed by optical microscopy, differential scanning calorimetry, MEV and FT-IR.