1. Introduction
Consumers of processed meat, aware of the relationship between diet and health, are increasingly searching out meat products with higher nutritional value compared to their traditional counterparts. This is related to the growing awareness of the relationship between diet and the occurrence of chronic diet-related diseases [
1]. The meat products market is trying to meet the needs of consumers and their high requirements regarding food quality by introducing new, enriched products with functional and health-promoting properties [
1,
2,
3]. Functional foods are those products that, in addition to nutritional value, have a positive effect on the functioning of the body [
4,
5]. The meat industry essentially offers three options for the development of functional products, modification at the farm, raw material and meat product level. At the breeding stage, the activities include genetic selection; at the raw material stage, the choice of the method and level of nutrition, and dietary supplementation are chosen, most often controlling the fatty acid composition [
6,
7]. The enrichment of the nutritional value of poultry meat products can be achieved by using or increasing the share of ingredients considered functional in the processing of poultry meat, at the same time having a health-promoting effect, among others, fibre, essential fatty acids and vitamins [
7]. The pro-health values of meat products can be increased by the addition of biologically active substances, probiotics, elimination of synthetic additives and lowering the cholesterol content and energy value [
5]. Enriching meat products with natural bioactive compounds is one of the main trends used in the meat industry [
7], leading to a better-balanced diet and compensating for nutritional deficiencies [
3]. As indicated in the literature [
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19], due to the rich nutritional composition of hemp, amaranth and golden flaxseeds, they can be used for the production of food products with added value, and the ingredients contained in the bioactive substances predispose the production of healthy and functional food. Hemp seeds are considered to be one of the most nutritionally complete food sources. They are a rich source of fat with a favourable composition of fatty acids and protein. Hemp fat (oil) contains large amounts of bioactive compounds, among others, phytosterols, carotenoids and polyphenols of anti-carcinogenic and anti-inflammatory nature [
13,
14]. Protein in the form of estidine is characterised by a good amino acid composition and high digestibility and is a source of bioactive peptides with antioxidant activity. Hemp seeds are rich in natural antioxidants and other bioactive ingredients, such as phenolic compounds, tocopherols, carotenoids and phytosterols [
15,
16]. Amaranth seeds are characterised as having a high nutritional value, which results from the high protein content with a very favourable amino acid composition. Attention is drawn to the high content of dietary fibre and the presence of a valuable ingredient, squalene [
17]. A compound with antioxidant and chemopreventive properties, capable of binding free radicals. They are characterised by a high content of minerals and the presence of vitamins (B
1, B
2, B
6, E and niacin), as well as polyphenolic compounds [
18,
19]. Flaxseeds are a rich source of many chemical ingredients, valuable from the point of view of human nutrition. They contain about 40% fat, of which almost 60% are omega-3 fatty acids and only 15% omega-6 fatty acids. A valuable ingredient is fibre, which constitutes 28% of dry matter, also vitamin E, which is a natural antioxidant and protects the body’s cells against the harmful effects of free radicals. The mineral content of flaxseeds is 3–8% [
8,
10]. The amino acid composition of flaxseeds has unique biological properties. The high content of leucine, lysine and phenylalanine regulates hormonal activities, tryptophan has a positive effect on eyesight and also prevents skin diseases, and threonine participates in the transformation and absorption of other amino acids. Flaxseed and products derived from it contribute to lowering the content of triglycerides and LDL cholesterol while increasing HDL cholesterol [
9,
10].
Turkey meat obtained from the leg may be a valuable raw material for processed meat production due to its high nutritional value, favourable sensory features and broad processing possibilities [
20,
21,
22].
The aim of this study was to replace wheat roll in the recipe composition of poultry pâtés with a mixture of hemp, amaranth and golden flaxseed and to assess the effect of their inclusion on the nutritional value, physical and sensory properties and safety of the finished product.
4. Results and Overview
Yield is a processing feature that is mainly of economic importance and may affect the degree of water retention in the product and its juiciness. The additions of hemp seeds, amaranth and golden flaxseed used in the original recipe in all research groups significantly influenced (
p < 0.05) an increase in the yield of poultry pâtés (
Table 2). In studies by Bilek and Turhan [
32], lower losses during heat treatment of the finished products with the addition of flaxseed flour were shown, which resulted from moisture retention in enriched products. In a study by Novello et al. [
11], the addition of golden flaxseed lowered the water content of raw and boiled beef cutlets. In the study by Longato et al. [
17], poultry burgers with the addition of amaranth seeds and pumpkin seeds had a higher efficiency compared to control poultry burgers. In the work by Ostoja et al. [
19], it was shown that grits prepared from raw amaranth seeds had a positive effect on the ability to retain water in meat mass in pasteurised and sterilised canned meat, which allowed losses during cooking to be reduced. The better water retention capacity, consequently, had an effect on improving the tenderness, juiciness and taste of canned meat. Sharoba [
33] showed that sausages in which the addition of amaranth flour was used were characterised by higher efficiency after thermal treatment compared to the control group. The research by Kotecka-Majchrzak et al. [
15] shows that the addition of hemp in the form of dough did not have a significant effect on the culinary losses of pork and poultry meatballs.
An important role in shaping the colour of finished meat products, apart from the raw meat, may be played by additives and proportions of all ingredients used in the recipe [
11,
13,
15]. In our own research, the share of meat in all groups was the same, so it can be assumed that the colour changes of the finished products resulted from the amount and type of additives used. The obtained results of the assessment of the colour of the cross-section of poultry pâtés showed that the products with the addition of hemp seeds, amaranth and golden flaxseed in all tested groups were characterised by a brighter colour (
p < 0.05), a higher brightness parameter L* and a higher (
p < 0.05) degree of saturation towards yellow. Lower (
p < 0.05) saturation of the red colour compared to the control group was noted in group III with a share of 10% of flax, 6% of amaranth and 8% of hemp seeds, and in group IV with 8% of all the seed additives (
Table 2). Similar results of an increase in the brightness and saturation of the yellow colour and reduction of the red colour saturation of beef cutlets with the addition of 5% golden flaxseed seeds and 5% of flaxseed flour were obtained by Novello et al. [
11]. The addition of golden flaxseeds and by-products from these seeds were obtained earlier in studies by Bilek and Turhan [
32]. Colour changes resulting from the fact that the flavonoids present in flaxseeds react with proteins [
34] to form active pro-oxidative isomers, which result in the oxidation of myoglobin or metmyoglobin [
35]. In a study by Zając et al. [
13], the colour parameters of pork pâtés changed depending on the hemp ingredient used. The addition of hulled hemp seeds did not significantly affect the brightness (L*) of the final product or its degree of saturation towards yellow, but it had an influence on the degree of saturation of the colour towards red (a*). In the work by Ostoja et al. [
19], the colour of the content of canned meat was assessed after adding ground raw and expanded amaranth seeds. The addition of raw seeds reduced the redness of the meat mass to a greater extent than the expanded ones and the degree of saturation towards yellowness (b *) in both pasteurised and sterilised products. However, these visual changes were judged negative.
Texture assessment is of great importance for the acceptability of a product by consumers. The instrumental test of texture profile analysis (TPA) allows researchers to obtain parameters characterising the texture and complementing the sensory tests [
23]. Our own research showed that poultry pâtés with the use of seeds in all research groups were characterised by significantly (
p < 0.05) higher hardness compared to pâtés with the addition of wheat roll. The value of TPA parameters was influenced by the amount of ingredients used. The pâtés from group III, with 10% flaxseed content and 6% amaranth seed content, had higher hardness compared to other research groups. The analysis of the results of the Warner–Bratzler maximum shear showed a similar trend for the hardness of the pâté (
Table 2). Increasing the firmness (increase in cutting force) of chicken meat burgers with the addition of flaxseed flour was reported by Cócaro et al. [
8]. The authors showed that the hardness of the meat product increased with the increase in the content of the addition of flaxseed flour. In a study by Zając et al. [
13], the addition of hemp ingredients (hemp flour, hemp protein and whole hemp seeds) increased the hardness of pork pâtés measured by the TPA test. In the authors’ own research, it was noted that the changes in the parameters of the texture profile (springiness, gumminess and chewiness) depended on the amount and interaction between the ingredients of the pâtés. It can be assumed that the component having the greatest influence on the textural features was the addition of flaxseeds (
Table 2). Similar results were obtained by Zając and Świątek [
16] when evaluating pork-liver pâtés with the addition of hemp seeds and flaxseed. The effect of the addition of amaranth and quinoa flour on the springiness, gumminess and chewiness of meat nuggets was demonstrated by Verma et al. [
18]. Cócaro et al. [
8] indicated that the addition of golden flaxseed flour can be used as a healthy component of meat products, improving technological properties and the bio-functional potential of the product resulting from the content of bioactive compounds contained in the seed.
An indicator of the health safety of a meat product is the total number of aerobic bacteria. It was shown that the addition of a seed mixture allowed for obtaining products of good microbiological quality after 48 h of storage. In the conducted research, it was noted that the applied plant additives reduced the total number of microorganisms in poultry pâtés (
p < 0.05) in groups II and IV with a higher proportion of amaranth seeds. This can be explained by the fact that amaranth seeds contain squalene, a substance with antioxidant properties. In studies by Longato et al. [
17], it was reported that the addition of amaranth seeds ingredients increases the antioxidant properties of raw burgers.
Proteins are a basic nutrient, and their proper consumption, both in quantitative and qualitative terms, is of key importance for human health [
36]. In the conducted research, the use of a mixture of hemp seeds, amaranth and golden flaxseed as a substitute for a wheat roll had a beneficial (
p < 0.05) effect on increasing the share of protein in all research groups (
Table 3) and maintaining the high biological value of the protein (
Table 4). Poultry pâtés with a higher addition of golden flaxseeds (groups III and IV) had a higher content of essential amino acids (lysine, aspartic acid, leucine, isoleucine and arginine). An increase in protein content in meatballs with the addition of amaranth seeds was demonstrated by Verma et al. [
18] in beef cutlets with flaxseed flour by Novello and Rodrigues Pollonio [
10], and in pâtés with flaxseed by Novello et al. [
11]. Conversely, after adding flaxseed flour to pâtés, Bilek and Turhan. [
32] found a decrease in the protein content concurrent with an increase in the proportion of flaxseed flour.
The type of plant additives used had an impact on the increase in fat content in pâtés that included them (
Table 3) and had a positive effect on the quality of fats in products with the addition of seeds (
Table 5). The use of hemp seeds, amaranth and flaxseed had a beneficial (modifying) effect on the profile of fatty acids in pâtés that included them. In the results of the evaluation of pâtés from all experimental groups compared to pâtés from the control group, a significantly lower (
p < 0.05) share of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) is noticeable. Among the SFA fatty acids, both in the pâtés from the control group and from the experimental groups, the highest share of palmitic and stearic acids was found, while among the monounsaturated acids, oleic acid was the highest. Similarly, in studies by Bilek and Turhan [
32], Pelser et al. [
37] and Novello et al. [
11], palmitic and stearic acids predominated in the composition of saturated fatty acids, and oleic acid in the composition of MUFA. Reducing the proportion of saturated fatty acids in pâtés from the experimental groups by more than 20% is beneficial from a nutritional point of view because an excess of saturated fat in the diet may cause the development of cardiovascular diseases. The addition of our proprietary blend of oil seeds resulted in an over 60% increase in the content of polyunsaturated acids (PUFA), most abundantly including linoleic acid (
p < 0.05), which reduced the risk of cardiovascular diseases and complications related to obesity and diabetes [
38,
39]. The share of trans fatty acids in pâtés with the addition of wheat roll and pâtés from the experimental groups was similar (
p > 0.05). Therefore, the addition of the seed mixture instead of the wheat roll did not increase the proportion of trans fatty acids, which are unfavourable to human health and which may cause cardiovascular diseases [
40]. The share of omega-3 fatty acids beneficial for health was more than three times higher (
p < 0.05) in pâtés with the proprietary seed mix compared to pâtés from the control group, which may be related to the high content of alpha linolenic acid (C18: 3n-3) in flaxseeds [
38]. An increase in the content of omega-3 fatty acids after the addition of flaxseed to ground beef cutlets was also found by Novello et al. [
11].
In the conducted research, the ratio of omega-6/omega-3 fatty acids in the control group pâtés was unfavourable and amounted to 8:1, while in the pâtés with the proprietary mix of seeds, it was favourably narrowed, respectively, to 3:1 (group II), 2:1 (group III) and 3:1 (group IV). Due to these ratios of omega-6 to omega-3 fatty acids, pâtés with the proprietary seed mixture presented significantly higher nutritional value than pâtés with wheat roll. An improvement in the ratio of omega-6 to omega-3 fatty acids in beef cutlets with flaxseed flour was also found by Bilek and Turhan [
32].
The addition of the seed mixture caused a significant (
p < 0.05) increase in the ash content in all research groups (
Table 3). In the studies by Bilek and Turhan [
32] and Novello et al. [
11], the addition of flaxseed in the form of seeds and by-products increased the ash content in meat products.
Fibre is considered a dietary component with a beneficial effect on health and is a commonly used additive to functional food [
5]. Modern methods of producing meat products are based, inter alia, on adding dietary fibre to them [
1]. In our own research, the addition of plant components caused a significant (
p < 0.05) increase in the share of fibre in pâtés from groups II, III, IV compared to the product with the addition of wheat roll. Moreover, in studies by Zając et al. [
13], the addition of hemp ingredients (hemp flour, hemp protein, hulled and whole hemp seeds) increased the fibre content. In studies by Verma et al. [
18], to produce goat meat nuggets, amaranth (1.5%) and quinoa (3%) flour were used as a substitute for (refined) wheat flour. The result is high-fibre, gluten-free meat nuggets. The use of these additives had a positive effect on the quality of the physicochemical and sensory characteristics of the manufactured product.
Vitamins are organic compounds that do not provide energy, nor are they structural components of tissues but are necessary for the proper growth and development of the organism [
41,
42,
43]. Among the vitamins found in meat products, vitamin E, which is a natural antioxidant, deserves special attention [
41]. It prevents the oxidation of polyunsaturated fatty acids, the consumption of which should be correlated with the appropriate consumption of α-tocopherol [
44,
45]. In the conducted studies, poultry pâtés using a mixture of hemp seeds, amaranth and golden flaxseed from all research groups, compared to pâtés with the addition of wheat roll, were characterised by a significantly (
p < 0.05) higher share of both forms of vitamin E. A twofold higher content of tocopherol in pâtés with the addition of seeds can be considered another pro-health value of these products. In studies by Dominguez et al. [
46], the effect of replacing animal fat with olive oil was an increase in the content of α-tocopherol. However, there are few reports on the use of plant supplements as vitamin supplementation in meat products.
An important issue in the production of functional and enriched food is to maintain the appropriate sensory characteristics so that enriched meat products do not differ from traditional recipe products and are accepted by the consumer. The results of the sensory evaluation of poultry pâtés indicate that the plant additives used in research groups II, III and IV had a positive effect on the odour intensity and desirability, as well as juiciness, compared to the control group pâtés. However, the desirability of flavour and binding were rated highest for pâtés from group IV, with an 8% share of plant additives. According to Sharoba [
33], juiciness, understood as the amount of juice released during chewing, is considered as a desirable sensory feature because it provides an excellent contrast for texture. In the case of ground meat products, the higher firmness of the products does not always reduce their quality. In the case of ground products, the consumer expects from such a product slicing characteristic, which results in better bonding and, at the same time, is characterised by greater firmness. In our own research, the spreadability and tenderness of pâtés with the addition of a mixture of hemp seeds, amaranth and golden flaxseed were assessed to be lower compared to the pâtés with the addition of wheat roll (
Table 6). In studies by Zając et al. [
13], the overall acceptability of pâtés with the addition of hemp ingredients (hemp flour, hemp protein and whole hemp seeds) was lower for the enriched products; only the taste of the product with the addition of hulled hemp seeds was comparable to the control product. As reported by Kostecka-Majchrzak et al. [
15], the use of hemp pulp (a by-product of cold oil pressing) may have a positive effect on the sensory characteristics of meatballs but the share of the hemp product should not exceed 2.6%. As demonstrated by Longato et al. [
17], natural ingredients (amaranth and pumpkin seeds) used in the production of poultry burgers had no significant effect on sensory characteristics; only burgers with 2% amaranth seeds were rated higher for juiciness and overall acceptability compared to the control burgers. In turn, Verma et al. [
18] indicated that the addition of amaranth seeds in the range of 1.5% increased the acceptability of all sensory features of goat meatballs. In studies by Bilek and Turhan [
32], it was noted that the addition of flaxseed flour obtained from flaxseeds had an impact on the assessment of sensory features (appearance, tenderness, juiciness and general acceptability); however, along with the increasing percentage of flaxseed, the sensory quality of beef cutlets worsened. The overall sensory quality of the products decreased significantly after the addition of 6% flaxseed flour.