1 Introduction

In India, the traditional wisdom concerning the preparation and preservation of food along with its healing effect has been accustomed for many generations. The traditional food in India has a long association with the local community and their preparation varies within the country. Most of the traditional food prepared in India makes use of functional ingredients during preparation and hence has numerous health-beneficial characteristics and can be considered functional food [1]. The functional ingredients include dietary fibres, prebiotics, probiotics, antioxidants, anti-inflammatory, anti-diabetic, and anti-ageing components [2,3,4]. The traditional dietary pattern in India has usually evolved from the rich culture which uses different ingredients in preparation of their local cuisines, mainly consisting of locally grown crops, which makes the traditional food unique [2]. Indian food brings forth riots of tastes/flavours originating from diverse cultures and traditions.

The epicurean tradition of the western state of India, i.e. Maharashtra, can be well explicated from the same perspective. The geographical terrain of this state displays a unique patchwork of eating habits that extends from the saliferous cuisines of coastal areas to the rustic/bucolic cuisines of the mainland. The traditional cuisine of Maharashtra state is among the most wholesome cuisines of the Indian subcontinent. One of Maharashtra's most consumed and signature dishes is a sweet flatbread, commonly known as ‘Puran Poli,’ usually prepared as a sweet dish during festival season in the state [5]. The ingredients used for the preparation of Puran Poli have an important role to play in the development of flavour and taste. The Indian diet contains the perfect combination of cereals and pulses, which mutually supplement each other in terms of protein content and amino acid profile [6, 7]. Puran Poli is an example of mutual supplementation, containing both pulses and cereals. Typically, a Puran Poli is made by incorporating stuffing of cooked chickpea, jaggery and cardamom (optional) mixture into flat bread made by kneading cereal dough in oil. The Puran poli is nutritionally rich as it is a source of protein, carbohydrates, fat, fibres, and minerals [8]. The Puran poli is highly perishable and has a shorter shelf life of around 12–24 h due to the formation of moulds, ropiness, and deterioration of texture [9]. Puran poli is not only consumed in Maharashtra state, but it is also prepared in other Indian states like Karnataka (Holige), Tamil Nadu (Poli), Andhra Pradesh (Bobatlu), Gujarat (Vermi), and Kerela (Lanchipoli). The preparation method, texture, and sensory attributes of Puran poli vary with changes in the geographical location within the country [10]. Recently, the focus of research has been more towards innovative methods and functional ingredient applications in food products. The research on traditional foods like Puran poli is limited. Hence, the aim of the present review is to highlight the importance of each ingredient used in the preparation of Puran poli, the method of preparation, the nutritional characteristics of the Puran poli, important characteristics of Puran poli, and, more importantly, the strategies to extend the shelf life of traditional Puran poli. The present review will help entrepreneurs and researchers to commercialize the preparation of Puran poli to meet the increasing demand from consumers.

2 Technological importance of ingredients

2.1 Chickpea

Chickpeas are one of the important ingredients used in the formulation of Puran (internal stuffing of Puran Poli). Chickpea displays a good nutritional profile, containing major and minor constituents, including proteins, carbohydrates, lipids, minerals, vitamins, isoflavones and dietary fibres [11]. Chickpea is a very good source of protein, containing a total of eighteen amino acids, out of which eight amino acids fall under the category of essential amino acids. Chickpeas also contain unsaturated fatty acids, including oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3) [11]. Additionally, chickpea is a good source of sodium, potassium, iron, copper, zinc, calcium, and magnesium. Chickpea contains an important class of compounds known as isoflavones, like genistein, calycosin, ononin, formononetin, biochanin, and sissotrin and studies have shown that these components are biologically active against health complications like diabetes, hyperlipidaemia, cancer, cardiovascular disease, osteoporosis etc. [12,13,14,15] The bioactive components have also exhibited properties like antioxidant, antifungal, contraceptive, antimicrobial, antiallergic, and antihypertensive properties [16,17,18]. The good nutritional composition and presence of the biologically active component make chickpeas a healthy ingredient in the formulation of Puran poli. A recent review by Sehar et al. [13] has detailed the effectiveness of chickpeas against various types of cancers like breast, colon, blood, and cervical cancer. The chickpea contains dietary fibres and prebiotic components that have numerous health benefits. The raffinose family oligosaccharides found in chickpeas have good prebiotic potential, as studied by Hussein et al. [19] and Pandae et al. [20]. The amino acid profile of chickpeas shows the presence of eight essential amino acids. However, chickpeas lack sulphur-containing amino acids like methionine and cysteine; this lack of amino acid is overcome by the utilization of cereals in preparation of poli used as a flatbread into which the stuffing of Puran (made using chickpea and jaggery) is incorporated. This is an example of mutual supplementation of pulses and cereals, as the deficiencies of amino acids in pulses are mutually supplemented by the amino acids contributed by cereals. The lipid profile of chickpeas is a very good source of polyunsaturated and monounsaturated fatty acids, along with nutritionally rich components like tocotrienols, tocopherols, and sterols. The α-tocopherol content of chickpeas (8.2 mg per 100 g) is the highest among all the pulses; the content of folic acid, riboflavin, pyridoxine, niacin and pantothenic acid is also higher in chickpea [11]. In a nutshell, chickpea is a storehouse of health-friendly components along with the major food constituents, making it an ideal ingredient in the formulation of Puran used as stuffing in preparation for Puran poli.

2.2 Jaggery

Jaggery has been used as a natural sweetener in food preparation since ancient times. A good quality jaggery has a hard texture, crystalline structure, sweet taste, and a low moisture content [21]. Jaggery is an important part of Indian culture as it is not only used in food applications, but history also talks about the medicinal use of jaggery in Indian Ayurveda medicine [22,23,24,25]. Jaggery is a functional ingredient used in the preparation of Puran poli because it is a source of minerals, vitamins, phenolic components, carbohydrates (glucose, fructose and sucrose), and proteins that are required for the normal growth of human beings [26]. The nutritional composition of jaggery (100 g) shows the presence of a good amount of minerals like calcium (40–100 mg), potassium (20–90 mg), sodium (19–30 mg), iron (10–13 mg), magnesium (70–90 mg) and vitamins like vitamin A (3.8 mg), vitamin B1/B5/B6 (0.01 mg), vitamin B2 (0.06 mg), vitamin C (7 mg), vitamin D2 (650 mg), vitamin E (111.3 mg). The carbohydrate content varies between 85% and 90%, among which glucose/fructose are 1–7 g, sucrose 75–85 g and protein content is about 1.7% (approximately around 280 mg/100 g) [27, 28]. The jaggery contains a good amount of phenolic components, which include gallic acid, ferulic acid, vanillic acid, 4‐4-hydroxyphenyl acetic acid, and gentisic acid [29]. The studies have also reported the presence of flavonoids (0.4–0.6%), syringic acid, ferulic acid, vanillic acid, protocatechuic acid, chlorogenic acid, and p-coumaric acid (Fig. 1) [30]. The GC-O-MS analysis of jaggery was studied by Chen et al. [31] to check the presence of bioactive aromatic compounds. The author reported the presence of 2‐acetylfuran, dibutyl phthalate, 2‐methoxy‐4‐acetylphenol, 2‐acetylpyrrole, 2‐formylpyrrole, dimethyl sulfoxide, 1,3‐dimethylbenzene, 2‐ethyl‐1‐hexanol, phenylacetic acid, 3‐phenyl‐2‐propenoic acid, 2‐ethyl‐5‐methylpyrazine, 2,3,5‐trimethylpyrazine, 2‐acetyl‐6‐methylpyrazine, 2,6‐di‐tert‐butyl‐pmethyl phenol, 4‐ethenyl‐2,6‐dimethoxy phenol, 2‐methyl pyrazine, 5‐methyl furfuryl alcohol, 4‐allyl‐2,6‐dimethoxyphenol, dodecane‐1‐ol, 5‐methyl furfuryl alcohol, phenylacetic, and 4‐ethenyl‐2‐methoxyphenol in jaggery. The structural skeleton of some compounds is shown in Fig. 1. The presence of the phenolic bioactive components imparts therapeutic characteristics to jaggery, like cytoprotective, antibacterial, antioxidant, and neuroprotective [27, 32]. The nutritional profile of jaggery makes it an essential ingredient for the Puran poli preparation due to the presence of essential amino acids, vitamins, minerals, proteins, and bioactive components and its ability to be effective against various diseases.

Fig. 1
figure 1

Structural skeleton of bioactive components found in jiggery. Adapted from [27]

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2.2.1 Cereal

The poli used in making Puran poli is usually prepared using cereal grain, the commonly used cereal grain is wheat. The whole wheat flour is converted into dough, which is then used to prepare poli (Indian flat bread), into which the stuffing of Puran is incorporated. Wheat contains approximately 78% carbohydrates, 14% proteins and 2% fat as major constituents. Additionally, wheat also contains a significant amount of minerals (like iron, zinc) and vitamins (vitamin B and thiamine) [33]. The whole wheat flour used for making dough is also a rich source of fiber. The content of fibres in whole wheat flour is approximately in the range of 12–15%. However, the refined wheat flour contains low fiber, as a large fiber content is removed during the milling process. The most common fiber found in wheat is arabinoxylan, which is hemicellulose, and interestingly, these fibers are insoluble. These insoluble fibers are utilized by the probiotic bacteria as they serve as the prebiotic components posing numerous health benefits to humans [34, 35]. The protein content of wheat varies between 7 and 22%, and gluten is an important protein present in wheat, which accounts for more than 80%. The presence of gluten is very important in the formation of an elastic dough that can be easily rolled into flat bread (poli) [33]. Wheat has a good antioxidant profile due to the presence of tocopherols, flavonoids and phenolic acid. The phenolic acids present in wholewheat flour include ferulic acid, caffeic acid, vanillic acid, syringic acid, sinapic acid, and p-coumaric acid, which have potential antioxidant characteristics [36, 37]. The health-beneficial characteristics of whole wheat flour due to the presence of phenolic components, minerals and vitamins make it an ideal ingredient in the preparation of Puran poli.

2.2.2 Other ingredients

The other minor ingredients include cardamom, nutmeg, edible oil, etc.; the cardamom, nutmeg, fennel, and ginger are used to spice the cooked chickpea. The minor ingredients are added to the flatbread to enhance the sensory profile. However, these ingredients also have health-friendly properties [38]. These ingredients are used in dry powder form to enhance the flavours of Puran and enhance the palatability of Puran poli. Cardamom is obtained from the seeds of Elettaria cardamomum and has a long history of use in traditional Indian food products. The flavour profile is the main attraction for the use of cardamom in food products, including industrially processed food and for household cooking. Additionally, cardamom is also known to have numerous medicinal characteristics owing to its phenolic profile. The Ancient Indian traditional medicine shows the use of cardamom due to its medicinal properties like diuretic, antibacterial, stomachic, antiseptic, expectorant, cardiotonic, anthelminthic, etc., and these all positive effects are well studied and supported by clinical studies available in the literature [39, 40]. Another ingredient is edible oil, which is added in the process of dough-making. The oil provides good lubrication to the dough, which improves the texture and rheology of the dough and makes dough handling easier [41]. The edible oil serves as the source of different fatty acids like polyunsaturated fatty acids, essential fatty acids, etc. Some researchers have also focused on the addition of edible oil containing medium-chain fatty acid in Puran poli preparation. Jadhav and Annapure (2022) reported that Puran poli prepared using oil containing medium-chain fatty acid showed good physicochemical, textural and sensory attributes. The Puran poli also showed a good oxidative profile with insignificant change in the peroxide value till 30 days of storage. The peroxide value (PV) of Puran poli stored at 4 ± 2 °C was constant for the first 15 days, and after that, it showed a marginal increase; the initial PV of 0.090 meq/ kg increased to 0.098, 0.114, 0.120 meq/kg on 20, 25 and 30 days of storage respectively. The initial PV of Puran poli stored at 25 ± 2 °C was constant for the first 10 days of storage, and then it increased to 0.112, 0.131, 0.158, and 0.180 meq/kg on 15, 20, 25, and 30 days respectively (Jadhav and Annapure 2022). Apart from this, nutmeg powder is also used in small quantities as a flavouring component to enhance the palatability of Puran poli. Nutmeg has many functional characteristics and health-friendly attributes like antifungal, anti-inflammatory, and anti-diabetic, helps in digestion and liver detoxication, prevents cardiovascular diseases and maintains respiratory health [42, 43]. All the ingredients used in the preparation of Puran poli have numerous health benefits, which make Puran poli a unique food for human consumption. However, Puran poli as a traditional food has just remained in household cooking and there are no food industries which have focused on the commercial production of Puran poli on a large scale. In the future, research should be done between academia and industry to optimize the production process for the Puran poli to meet the increasing demand from consumers across the globe, as the migration of people from Maharashtra has taken their food to every corner of the world and the Puran poli is among the most liked food in the world.

3 Flow of preparation

The preparation of Puran poli is traditionally done in three major steps, which involve the preparation of Puran (stuffing), preparation of dough, and preparation of Puran poli. Each and every step in the preparation process plays an important role in giving good textural and sensory attributes to the Puran poli.

3.1 The traditional method of making Puran

Puran is the internal stuffing which gives Puran poli its unique taste and is usually sweet due to the presence of jaggery. The chickpea split and jaggery are the major ingredients used for the preparation of Puran. The known amount of split chickpea is washed thoroughly with water and then pressure-cooked for about 25–30 min or till it is completely cooked. In some cases, the chickpea splits are soaked (2–6 h) in water prior to pressure cooking, which helps in achieving the desired texture and flavour in Puran poli. A recent study by Kardile et al. [44] reported the hydration kinetics of chickpea splits and the effect of soaking on the physicochemical characteristics of Puran. The authors reported soaking as a beneficial approach before cooking as it reduces the cooking time by more than 80%, leading to less energy consumption. The optimized conditions resulting in the preparation of good quality Puran was soaking for 135 min at 30 °C and then cooking at 100 °C for 10–12 min. However, the optimized conditions may differ depending on the morphology and quality of the chickpea split, but this will help in engineering the equipment which can be used for large-scale preparation of Puran [44]. After cooking chickpeas split, they are mixed with the jaggery, and the mixture is heated for a certain period of time so that the jaggery melts and is uniformly distributed in the mixture. The heating process is continued till the entire jaggery melts and the caramel flavour starts coming. At this stage, the flavouring ingredients like nutmeg powder and cardamom are added to the mixture and mixed thoroughly. The mixture is then strained using a strainer to obtain a soft mass of Puran. The resulting mixture is known as a Puran that is used as stuffing in preparation for Puran poli. The flowchart for the preparation of Puran is diagrammatically shown in Fig. 2.

Fig. 2
figure 2

Flow chart showing the preparation of Puran

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3.2 Dough preparation and Puran poli formation

The dough preparation method is simple and is usually done by using a dough mixer. Whole wheat flour is mixed with a known quantity of lukewarm water and a pinch of salt for taste. The mixture is kneaded for 5–7 min, followed by the addition of oil to make the dough soft. The addition of oil also provides good lubrication, which assists in the process of kneading dough, thus forming a soft and good texture dough with good rheological characteristics. The dough is kneaded till the desired consistency and elasticity is obtained [10]. The dough is allowed to rest for 10–15 min so that it can be easily rolled into flat bread sheets. The dough preparation methods play an important role; the dough should not be too hard as it will become difficult to roll it in thin sheets. If the dough is too soft, then it will stick onto the roller board and roller pin while making flat sheets.

The third step after the preparation of Puran and dough formation is the preparation of Puran Poli. The known amount of dough is taken and made into thin sheets, followed by the incorporation of the stuffing of Puran in the dough. The stuffing is done in two ways; the first way is that the dough is rolled into sheets, and Puran is placed on it, followed by rounding the dough and then again rolling it into thin sheets. In the second way, the dough is made into thin sheets and a thick layer of Puran is uniformly distributed on the sheets, followed by placing another thin sheet of dough on the Puran and then slightly rolling it to form a Puran poli. After rolling of Puran poli, it is then cooked on the heated pan from both sides till both sides turn into a light brown colour. A small quantity of ghee/oil is applied on both sides of the Puran poli while roasting on the heated pan. It assists in the development of the desired flavour and colour, making Puran poli more appealing (Fig. 3).

Fig. 3
figure 3

Flowchart showing preparation of Puran Poli

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4 Physicochemical and sensory characteristics of Puran poli

The physicochemical, textural and sensory characteristics of Puran poli are important from the consumer acceptance point of view. The Puran poli is a sweet flat bread that contains carbohydrates, fat, proteins, and minerals as contributed by the individual ingredients used in the preparation of Puran poli. The Puran poli prepared using whole wheat flour is rich in carbohydrates, dietary fibre, minerals and certain vitamins. The chickpea splits serve as the source of proteins, and the use of cereals and pulses in Puran poli mutually supplement each other and provide all essential amino acids. The use of edible oil serves as the source of polyunsaturated fatty acid, essential fatty acid, and fat-soluble vitamins. Additionally, these components also serve as the source of biologically active components as discussed in previous sections. The nutritional analysis of Puran poli was studied by Ware et al., (2018), the authors reported that the Puran poli contained > 16% protein, > 50% carbohydrates, > 15% fat, 30% moisture, 79 mg/100 g calcium, and 2.98 mg/100 g iron. However, the authors have not studied the presence of bioactive components that are contributed by all the ingredients used in the formulation of Puran Poli. Though they are many health-beneficial components present in the ingredients used for the preparation of Puran poli. However, there are no studies reported in the literature that have focused on the quantification of these bioactive components in Puran poli. Future research should focus on the direction of evaluating the presence of biologically active components in the Puran poli. The textural characteristic of Puran poli is determined using a texture analyzer having a probe that is allowed to penetrate the sample. The Puran poli containing good quality Puran is usually pliable, soft and can easily be pieced with minimum force. The texture of Puran poli is dependent on the quality of Puran used in the stuffing of Puran poli. Puran containing a higher quantity of jaggery becomes sticky, and Puran containing less quantity of jaggery will become too dry, and in both conditions, it negatively affects the texture of Puran poli [45]. Finally, the most important characteristic is the sensory attributes that decide the consumer acceptability of the product. The colour of the outer crust is light brown, and it depends on the proper roasting of the flatbread. Usually, a small amount of ghee/oil is applied on the outer surface of the flatbread during roasting, which helps in developing a light brown colour. The Puran poli should appear intact with the Puran inside the flatbread. If the rolling of flatbread is not done properly, then there are chances that the outer covering may develop cracks, and Puran may come out; this will negatively affect the appearance and reduce consumer acceptability. The other sensory attributes like taste, flavour, and aroma of the Puran Poli are governed by the Puran [46]. The good taste of Puran Poli is due to Puran; all the individual ingredients used in making Puran contribute to its taste and flavour. Hence, optimizing the ingredients and carefully monitoring the process of Puran preparation assists in the formulation of delicious Puran poli.

5 Shelf stability

The Puran poli contains a higher proportion of water, which favours bacterial growth, and Puran poli hardly have a shelf life of 24–48 h at ambient temperature. The increase in the storage period decreases the texture, sensory profile and palatability of Puran poli. As the demand for traditional food is increasing across the globe, there is a need to develop certain strategies to enhance the shelf life of traditional foods like Puran poli. The Puran poli is not only liked by the local population of Maharashtra state of India, but it has become popular across the globe due to its delicious taste and mouth-watering flavours. To cater for the demand, the food industries should step forward to work on the large-scale production of Puran poli, having a longer shelf life. Some of the researchers have started working on the process optimization for Puran poli that will help in commercializing the product. A single step towards the process of commercialization was taken by producing Puran in an easy and convenient manner by Kardile et al. [47]. The author optimized the process for the production of instant Puran powder which can be used in the preparation of Puran poli. The instant Puran mix showed good sensorial acceptance in terms of colour, appearance, taste, texture and overall acceptability. The authors concluded that vacuum drying of Puran at 60 °C is the energy efficient and faster process of producing instant Puran powder. In another study by Jadhav and Annapure, (2022), the use of medium-chain triglyceride instead of conventional oil was shown to have a beneficial effect on the microbial and oxidative stability of Puran poli. The peroxide value showed a marginal increase from 0.09 (0 days) to 0.18 meq/kg (30 days) at 25 °C with no bacterial growth. However, there was growth of yeast and mould after 25 days of storage at 25 ± 2 °C, but this was within acceptable limits and had no effect on the texture of Puran poli. The texture remained firm and kept Puran intact in the flatbread throughout the storage period. The medium-chain fatty acids released from the glycerol skeleton showed an anti-bacterial effect, which prevented the growth of bacteria to some extent, and the Puran poli showed excellent overall acceptability for 30 days [48]. The problem related to the growth of yeast and mould can be resolved by using a proper packaging material, which can further extend the shelf life of Puran poli and keep it fresh till it reaches the consumer. The ideal packaging material should be able to provide barrier against oxygen and moisture, so that the Puran poli is protected from the microbial growth and development of rancidity. The packaging materials like coextruded laminate pouches and low-density polyethylene were used as a packaging material for Puran powder. The accelerated shelf life study of instant Puran powder was done at 38 ± 2 °C temperature and relative humidity of 90 ± 2% for 120 days by Kardile et al. [9]. The author reported the predicted shelf life of Puran powder stored in laminate pouches to be 13.41 months and Puran powder stored in low density polyethylene to be 2.42 months. The initial water activity of 0.33 increased to 0.65 and 0.36 for Puran powder stored in low density polyethylene and laminate pouches at 28 °C respectively. The total plate of Puran powder stored in low density polyethylene increased from 4.0 × 103 CFU/g to 23.0 × 103 CFU/g after 60 days at 28 °C. However, the total plate count of Puran powder stored in laminate pouches increased from 4.0 × 103 CFU/g to 15.1 × 103 CFU/g after 120 days of storage at 28 °C. This study showed the differences in the shelf life of Puran powder based on the use of different packaging material, the coextruded laminate pouches were able to extend the shelf life of Puran powder till 4 months as compared with the low density polyethylene pouches [9]. The study has just focused on evaluating the suitability of packaging material on shelf life of Puran powder, however the study may not be applicable to the Puran poli. Hence, the future research should work on developing strategies in terms of use of ingredient in Puran poli formulation that has anti-bacterial activity which will prevent the bacterial growth and use of oil like medium chain triglyceride or blend of oil that will enhance the oxidative stability of product. Additionally, the future research should undertake a comparative study to evaluate suitability of packaging material and its effect on shelf life of Puran poli. The future research in this direction will help in commercializing the Puran poli production at industrial scale to meet the increasing demand for the traditional food across globe.

6 Concluding remark and future scope

Puran poli is the signature dish of Maharashtra state of western India, and now this traditional food has crossed the state and country boundaries and has become the most liked food among the consumers across globe. The Puran poli is exported to United States of America, Europe, Australia etc. from India to meet the increasing demand from consumers. The soft texture and sweet delicacy make the Puran poli the more delicious and unique dish among the traditional foods in India. The ingredients used in the preparation of Puran poli have numerous health benefits owing to the presence of biologically active components. The main ingredients used in the preparation of Puran are chickpea splits and jaggery, both of which are good for human health. The chickpea used in Puran and wholewheat flour used in dough making both mutually supplement each other and serve as the source of essential amino acids. The ingredients like oil/ghee, cardamom, and nutmeg powder add to the nutritional profile of Puran poli. The preparation method of Puran poli includes three steps viz; preparation of Puran, dough making and Puran poli preparation. Each step in preparation for Puran Poli plays a vital role in the development of the sensory profile and texture of Puran poli. The moisture content of Puran poli is higher, and hence it makes it highly perishable with a limited shelf life of 1–2 days. The scientific studies on traditional food are not given much importance, and hence, there are limited studies reported in the literature focusing on the preparation and shelf-life study of Puran poli. Keeping in mind the increasing demand for the Puran poli, the industries and academic institutes should collaborate for future studies on optimizing the process parameters and ingredients for commercial scale preparation of Puran poli. Future research should also focus on the comparative study to evaluate the suitability of different packaging materials to enhance the shelf life of Puran poli to a maximum extent without compromising the sensory and textural attributes. Future research will help contribute towards the advancement in the commercialization of traditional cuisine by overcoming the research gap in the field of traditional foods.