Co-extrusion of pearl millet-whey protein concentrate for expanded snacks

Evaluating the 3D printability of pearl millet flour with banana pulp blends

BACKGROUND

Three-dimensional (3D) food printing is a promising method for developing nutritious snack foods with complex and customized structures. In this study, to develop a pearl millet-based snack formulation, the printability of pearl millet flour (PMF) was assessed, without and with the addition of banana pulp (BP), a natural taste and flavor enhancer, at five different levels (PMF:BP of 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100).

RESULTS

The water activity significantly decreased with increases in the proportion of BP; higher water activity was exhibited at 100:0 (0.99). The BP proportion influences all the color values (redness: 2-11; yellowness: 17-31.87; total color difference: 2-17). All formulations exhibited shear-thinning behavior (n = 0.02-0.49) and higher hardness (0.2-0.4 N), but not all were printable. A significant decrease in adhesiveness (-0.2 to -0.03 N s) and higher storage modulus (2000-6000 Pa) occurred with an increased proportion of BP. Findings from detailed rheological behavior assessment (static, dynamic and three-interval thixotropy tests) better correlated with trends observed during 3D extrusion printing. The highest yield stress was attained (80 Pa) in the 100:0 formulation. From the thixotropy test, more deformation (>80%) and recovery (>100%) were attained by three of the formulations (100:0, 80:20, 60:40). Overall, the best constructs were obtained (based on the visual sensory characteristics) for the 60:40 formulation printed at 600 mm min-1 printing speed and 240 rpm extrusion motor speed through a 1.22 mm nozzle.

CONCLUSION

The findings of this work will provide valuable insights into the development of novel millet-based 3D printed foods. © 2024 Society of Chemical Industry.

Effect of physicochemical properties on popping characteristics of selected pearl millet varieties

BACKGROUND

Pearl millet, commonly known as 'Bajra', is a nutrigrain, mostly used in pulverized form to make unleavened pancakes, dumplings, porridge, etc., in India. Popping, a traditional method of millet processing, is used in making ready-to-eat snacks. Pearl millet is underutilized in India. The present work aims to study the effect of the parameters of pearl millet such as variety, chemical composition, pericarp thickness, amylose content, and processing temperature on the volume expansion ratio and sensory properties of popped pearl millet.

METHODOLOGY

A conventional salt-popping technique was used at three different temperatures (220 °C, 240 °C, and 260 °C) for five pearl millet varieties (ABPC 4-3, AHB 1269, AHB 1666, AIMP 92901, and PPC-6). Parameters such as color, diameter, density, amylose content, pericarp thickness, and proximate composition were analyzed. Popping characteristics such as volume expansion ratio, popping yield, and sensory properties of popped grains were studied.

RESULTS

It was observed that pericarp thickness and amylose content were positively correlated with the popping qualities of grains. AIMP 92901 offered more desirable properties such as suitable moisture content (87.5 g kg^-1 ), lowest equivalent diameter (2.07 mm), highest bulk density (0.84 g cm^-3 ), true density (1.41 g cm^-3 ), pericarp thickness (30.82 μm), and amylose content (19.75 g kg^-1 ) than the other varieties that were studied. Hence, the highest popping yield (72.83%) and expansion ratio (6.15) was observed in the AIMP 92901 pearl millet variety at 260 °C.

CONCLUSION

Conventional salt popping at 260 °C yielded the best popping characteristics. Pearl millet variety AIMP-92 901 developed by VNMKV (Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani), Parbhani was found to have more desirable popping characteristics (in terms of all the parameters explained in results). © 2022 Society of Chemical Industry.

Probing nutritional and functional properties of salted noodles supplemented with ripen Banana peel powder

Banana peel is appreciated for higher dietary fiber, phenolics, flavonoid contents, and minerals (particularly iron, calcium, and potassium), despite being a waste product. After drying, it can be processed into powder/flour to be combined with wheat flour (WF) for development of value-added products. In this study, we substituted WF with banana peel powder (BPP) at supplementation rates of 5, 10, and 15%, and evaluated their suitability to develop salted noodles. The results showed that the composite flour with 15% BPP had significantly higher protein, ash, and crude fiber content as compared to control. Higher antioxidant capacity was observed in composite flour noodles: total phenolics content (TPC), total flavonoid content (TFC), ferric reducing power (FRAP) and DPPH reducing power were increased up to 278, 260, 143 and 13 percent respectively in the noodles containing 15% BPP as compared to control (100% WF). On the other hand, values for viscosity decreased up to 22% with addition of BPP in WF. Furthermore, water absorption capacity and cooking losses were increased up to 15 and 13 percent respectively with 15% BPP incorporation in WF. Results for sensory evaluation demonstrated that noodles with 10% BPP scored highest for sensory profile.

Graphical abstract

Use of Legumes in Extrusion Cooking: A Review

The traditional perception that legumes would not be suitable for extrusion cooking is now completely outdated. In recent years, an increasing number of studies have been conducted to assess the behavior of various types of legume flours in extrusion cooking, proving that legumes have excellent potential for the production of extruded ready-to-eat foods by partially or totally replacing cereals. This review identifies the optimal processing conditions for legume-based and legume-added extruded foods, which allow the improvement of the expansion ratio and give the extrudates the spongy and crisp structure expected by consumers. In particular, the effect of the individual processing parameters on the physical-chemical and nutritional properties of the final product is highlighted. The extrusion cooking process, indeed, has a positive effect on nutritional characteristics, because it induces important modifications on starch and proteins, enhancing their digestibility, and reduces the content of trypsin inhibitors, lectins, phytic acid, and tannins, typically present in legumes. Therefore, the extrusion of legume flours is a viable strategy to improve their nutritional features while reducing home preparation time, so as to increase the consumption of these sustainable crops.

Coconut meal: Nutraceutical importance and food industry application

In tropical regions coconut is the tree of great significance: it provides millions of people with food, employment, and business opportunities. The fruit is referred to as ‘miracle fruit’ due to its inherent rich profile of macro- and micro-nutrients for human nutrition and health. Different products, such as coconut water, milk, raw kernels, oil and desiccated coconut are commercially processed. Coconut flour is a byproduct of coconut milk and oil industry which is made from coconut meal leftover after processing. Being a rich source of dietary fibre and protein, it has found numerous applications in different functional foods. Coconut flour can be successfully incorporated into various food products, such as bakery, extruded products, snacks, and sweets. It has antidiabetic and anticancer effects, prevents cardiovascular diseases, and improves immune function. Coconut flour is also gluten-free and its nutritional composition is quite comparable to that of wheat flour. Gluten-free food products enriched with coconut flour are a healthy and viable option for the people with celiac disease. In this paper, we summarised the present use of coconut flour. There is an apparent need to convert the food processing byproducts into functional ingredients in order to implement their environment-friendly and efficient utilisation.

Whey valorization: current options and future scenario – a critical review

Purpose

The purpose of this paper is to review the advanced technologies and approaches for utilization of waste generated in dairy industry. Whey is highly contaminated, with a high organic load around 100,000 mg O2/L COD (chemical oxygen demand), and is not used for further processing. The waste generated in different food industries can be utilized in different value addition product with the help of advanced technology.

Design/methodology/approach

Major well-known bibliometric information sources are the Web of Science, Scopus, Mendeley and Google Scholar. Several keywords like nutrition value of whey, whey utilization, whey valorization, whey technologies, whey beverages, fruit-based whey beverage, carbonated beverage, probiotic or alcoholic beverages, herbal beverage, fermented beverage and current scenarios were chosen to obtain a large range of papers to be analyzed. A final inventory of 126 scientific sources was made after sorting and classifying them according to different criteria based on topic, academic field country of origin and year of publication.

Findings

The comprehensive review of different literature, data sources and research papers seeks to find and discuss various sustainable solutions to this huge waste generated from milk industry. The sustainable use of whey for production and conversion in different types of products can uplift the bio-based economy of industries and thereof national/international economy. The recent upsurge in consumer interest for health-promoting products has opened up new vistas for whey beverages and other whey products research and development.

Originality/value

The paper draws out different sustainable characteristics and technology of whey products available in market, as well as potential products to be launched in the market. Interestingly, over the past few years, dairy industries have applied various technologies to process cheese whey and are in search of new products which can be prepared from the by-product. This review discusses on the recent research development of whey valorization with particular reference to technologies used in the addition to their commercial availability and a way forward.

Wheat-Fenugreek Composite Flour Noodles: Effect on Functional, Pasting, Cooking and Sensory Properties

Composite flour noodles were prepared by blending fenugreek flour (FF) with wheat flour (WF) at a replacement level of 2%, 5%, 7% and 10%, respectively. The chemical, functional, and pasting properties of different flour blends were assessed to check its suitability for noodle making. FF exhibited significantly (p 0.05) high protein (28.5%), crude fibre (7.2%), fat (4.9%) and ash content (3.6%) as compared with WF. Water absorption capacity, water solubility index, oil absorption capacity, foaming capacity and emulsion capacity showed an increase in values while the peak viscosity of flour blends decreased with increase in the level of FF. The noodles prepared with wheat-fenugreek flour blends showed higher cooking time, water uptake and cooked weight but less gruel solid loss as compared with control (100% WF) noodles. Noodles prepared with 93% WF+7% FF scored a satisfactory overall acceptability score for their sensory characteristics. Therefore, noodles with satisfactory eating, cooking, texture attributes can be prepared incorporating fenugreek flour up to a level of 7%, helps in exploring the health benefits of fenugreek.

Correlations between the physical properties and chemical bonds of extruded corn starch enriched with whey protein concentrate

The effects of extrusion temperature and whey protein concentration on the physical properties of corn starch were studied. Correlations between the physical properties of the extrudates and internal chemical bonds in proteins were studied using Pearson's statistical method.

Filler functionality in edible solid foams

We review the functionality of particulate ingredients in edible brittle foams, such as expanded starchy snacks. In food science and industry there is not a complete awareness of the full functionality of these filler ingredients, which can be fibers, proteins, starch granules and whole grains. But, we show that much can be learned about that from the field of synthetic polymeric foams with (nano)fillers. For edible brittle foams the enhancement of mechanical strength by filler ingredients is less relevant compared to the additional functionalities such as 1) the promotion of bubble nucleation and 2) cell opening-which are much more relevant for the snack texture. The survey of particulate ingredients added to snack formulations shows that they cannot be viewed as inert fillers, because of their strong hygroscopic properties. Hence, these fillers will compete with starch for water, and that will modify the glass transition and boiling point, which are important factors for snack expansion. Filler properties can be modified via extrusion, but it is better if that processing step is decoupled from the subsequent processing steps as mixing and expansion. Several filler ingredients are also added because of their nutritional value, but can have adverse effect on snack expansion. These adverse effects can be reduced if the increase of nutritional value is decoupled from other filler functionality via compartmentalization using micropellets.

The Effects of Fortification of Legumes and Extrusion on the Protein Digestibility of Wheat Based Snack

Cereal food products are an important part of the human diet with wheat being the most commonly consumed cereal in many parts of the world. Extruded snack products are increasing in consumer interest due to their texture and ease of use. However, wheat based foods are rich in starch and are associated with high glycaemic impact products. Although legume materials are generally rich in fibre and protein and may be of high nutritive value, there is a paucity of research regarding their use in extruded snack food products. The aim of this study was to prepare wheat-based extrudates using four different legume flours: lentil, chickpea, green pea, and yellow pea flour. The effects of adding legumes to wheat-based snacks at different levels (0%, 5%, 10%, and 15%) during extrusion were investigated in terms of protein digestibility. It was observed that fortification of snacks with legumes caused a slight increase in the protein content by 1%–1.5% w/w, and the extrusion technique increased the protein digestibility by 37%–62% w/v. The product developed by extrusion was found to be low in fat and moisture content.