The Effect of Algae or Insect Supplementation as Alternative Protein Sources on the Volatile Profile of Chicken Meat

Microalgae: An Exciting Alternative Protein Source and Nutraceutical for the Poultry Sector

Microalgae have garnered a considerable attention as a sustainable substitute as customary feed ingredients for poultry, predominantly due to their extraordinary nutritive profile and purposeful properties. These minuscule organisms are protein rich, retain an ample quantity of essential fatty acids, vitamins, minerals, and antioxidants, thus are capable of improving nutritive value of poultry diets. Microalgae comparatively delivers an outstanding source of protein containing substantial amount of innumerable bioactive complexes, omega-3 fatty acids in addition to the essential amino acids (methionine and lysine), crucial for optimal growth and development. Besides nutritional significance, microalgae have considerable immunomodulatory and antioxidant properties that help to reduce oxidative stress and enhance immune status, thereby improving the overall health and performance. Additionally, microalgae proved to induce antimicrobial and intestinal health benefits via upregulated gut eubiosis, promoting the colonization and growth of probiotic bacteria and offering protection against infections. These nutraceutical benefits are particularly important for sustainable poultry production and reducing the dependence on antibiotic growth promoters to produce antibiotic free food. This review aims to highlights multifaceted advantages of microalgae as a functional feed additive for poultry diet to support sustainable and efficient poultry production.

Spirulina (Arthrospira platensis) Used as Functional Feed Supplement or Alternative Protein Source: A Review of the Effects of Different Dietary Inclusion Levels on Production Performance, Health Status, and Meat Quality of Broiler Chickens

The broiler industry is pivotal in meeting the growing global demand for highly nutritious animal protein foods. Hence, there is a continuous interest in identifying novel, alternative, and even unconventional feed resources that could help sustainably support chicken meat production and quality. In this view, the microalga Spirulina (Arthrospira, formerly Spirulina, platensis), due to its unique chemical composition and some ecological advantages offered by its cultivation over traditional agriculture, has attracted great attention in the poultry sector for potential application in broiler diets, either as a functional supplement or a replacer of conventional protein sources such as soybean meal. The studies conducted so far seem to have confirmed many of the initial expectations regarding the advantages that may derive from dietary Spirulina supplementation, documenting its capacity to positively influence the intestinal and general health status of broiler chickens, leading to improved or preserved productive performance (under normal or challenging conditions, respectively), as well as to increased disease resistance and survivability. Furthermore, dietary Spirulina supplementation has been shown to induce positive changes in some important traits of broiler meat quality. However, at present, the inclusion of Spirulina in broiler diet, especially but not solely in relation to the use as an alternative protein source, presents several technical and economic limitations. To increase the overall awareness around the actual usefulness and practical usability of Spirulina as a novel natural component of the broiler diet, this review paper seeks to provide a comprehensive and integrated presentation of what is currently known about this topic, highlighting critical issues that are still pending and would require further research efforts.

Comparison of volatile compound profiles derived from various livestock protein alternatives including edible-insect, and plant-based proteins

In this study, the distinctive chemical fingerprints that contribute to the flavor characteristics of various protein materials, such as insects, plant-based protein, and livestock, were investigated. In edible-insects (Tenebrio molitor and Protaetia brevitarsis), aldehydes and cyclic volatile compounds were the predominant volatile components and had distinct flavor characteristics such as cheesy, sharp, green, floral, and sweet. In contrast, the relatively high levels of pyrazines and furans in plant-based protein materials, such as textured vegetable and pea protein. They included unique flavor properties characterized by sweet, fatty, grassy, creamy, and roasted. The primary volatile chemical group detected in livestock protein materials, such as a pork and a beef, was ketones. The pork sample showed specific flavors, such as alcoholic, green, and fruity, while a beef presented distinctive flavor, including creamy, fruity, and alcoholic. Based on the results, this research provided the understanding of the flavor aspects of diverse protein materials.

Impact of long-term feeding a high level of Spirulina combined with enzymes on growth performance, carcass traits and meat quality in broiler chickens

This study evaluates the effect of prolonged feeding with a high inclusion level of Spirulina, combined with peptidases, on broiler chicken's growth performance, digesta viscosity, carcass attributes and meat quality. The experiment involved 120 male broilers divided into 40 battery brooders, each housing 3 birds. Post 7-day acclimatisation with a corn and soybean-based diet, the birds were provided with one of four diets: a corn and soybean meal-based diet (CON), a mix incorporating 15% Spirulina (SP), a Spirulina-rich mix supplemented with 0.025% of commercial VemoZyme® P (SPV), or a Spirulina-rich mix supplemented with 0.10% of porcine pancreatin (SPP). The CON group had higher body weight and weight gain (p < 0.001) and a lower feed conversion ratio (p < 0.001) from day 7-21, compared to the Spirulina-fed groups. Spirulina-fed chickens significantly increased ileum viscosity (p < 0.05). Spirulina also elevated the weight (p < 0.05) of the duodenum and the length (p < 0.001) of the entire gastrointestinal tract compared to CON. Breast and thigh muscles from Spirulina-fed broilers displayed higher values of yellowness (b*) (p < 0.001), pigments (p < 0.05), and n-3 PUFA (p < 0.01), while n-6/n-3 ratio (p < 0.001) and α-tocopherol (p < 0.001) decreased relative to the CON. In conclusion, the introduction of a high level of Spirulina into broiler diets for an extended duration, has the potential to diminish birds' growth performance, possibly due to increased digesta viscosity. However, it does enhance the nutritional quality of the meat.

Lauric acid content in intramuscular fat is a reliable indicator of black soldier fly larvae meal consumption in Muscovy ducks

The present research investigated if intramuscular fatty acid (FA) profile could distinguish meat from ducks fed with black soldier fly larvae meal (BSFLM) during fattening. By using stepwise linear discriminant analysis on FA profiles of 96 meat samples, lauric acid (C12:0) was found to be the best predictor, accurately differentiating samples with only two misclassifications. The Fisher classification functions indicated that breast samples with lauric acid content above 0.222 % in intramuscular fat would be classified as BSFLM-fed. The Fisher classification functions were also effective in other poultry species fed BSFLM, with only two misclassified samples out of 42 samples from a dataset compiled from published papers. Misclassifications were linked to an unexpected lauric acid content in the intramuscular fat. In conclusion, given that BSFLM is the only relevant source of lauric acid in the diet, this fatty acid could identify meat from BSFLM-fed ducks and possibly other poultry species, warranting further exploration of other FA as potential identifiers of BSFLM-fed poultry.

Effect of Dietary Insect Meal and Grape Marc Inclusion on Flavor Volatile Compounds and Shell Color of Juvenile Abalone Haliotis iris

Almost 60% of the fish meal produced globally is used in aquaculture feeds. Fish meal production relies on finite wild-marine resources and is considered as an unsustainable ingredient. Insect meal (IM) is considered a sustainable source with high levels of protein suitable for growth promotion. Grape marc (GM) is a waste byproduct of the winery industry rich in pigments with antioxidant capacity. However, the inclusion of both ingredients can affect the flavor of the meat of abalone and the color of the shell due to different nutritional profiles. The aim of this study was to evaluate the effect of the dietary inclusion of IM and GM on the flavor volatile compounds and shell color of the juvenile Haliotis iris in a 165-days feeding trial. Abalone were offered four experimental diets with different levels of IM and GM inclusion and a commercial diet (no IM or GM). Soft bodies of abalone were used to characterize volatile compounds using solid-phase microextraction gas chromatography-mass spectrometry, and color changes were analyzed in ground powder of abalone shells using color spectrophotometry 400-700 nm (visible). The results showed 18 volatile compounds significantly different among the dietary treatments. The inclusion of IM did not significantly affect the flavor volatile compounds detected, whereas the inclusion of GM reduced volatile compounds associated with lipid-peroxidation in abalone meat. The inclusion of IM and GM did not significantly affect the lightness nor the yellowness, blueness, redness, and greenness of the ground shells. The supplementation of abalone feeds with GM can help to reduce off-flavour compounds which may extend shelf-life of raw abalone meat.

Dietary Dried Jujube Fruit Powder (DJFP) Supplementation Improves Growth Performance, Antioxidant Stability, and Meat Composition in Broilers

Nowadays, broiler production is faced with great challenges due to intensive culture modes, and chickens are more susceptible to oxidative stress. Consequently, synthetic antioxidants have been used to reduce this process, but their use has shown potential health risks. Thus, the use of natural ingredients has been suggested as a strategy to prevent oxidative stress. This study investigated how dietary dried jujube fruit powder (DJFP) supplementation influences the growth performance, antioxidant stability, meat composition, and nutritional quality of Cobb broilers. A total of 360 unsexed broilers (1-day-old) were randomly assigned to treatments that varied in DJFP levels: a basal diet without DJFP (control) and diets supplemented with 50 g/kg DJFP (P1), 100 g/kg DJFP (P2), and 150 g/kg DJFP (P3), with 9 replicates per treatment (90 broilers/treatment or 10 broilers/replicate). The results demonstrated improvement in the growth performance of broilers in terms of body weight (BW), body weight gain (WG), average daily body weight gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) following dietary DJFP supplementation. In addition, the antioxidant stabilities in the DJFP-treated broilers were improved and inhibited the production of lipid oxidation products compared with the control, with those in the P2 group showing the most marked effect. Moreover, dietary DJFP supplementation significantly increased (p < 0.05) the activity of antioxidant enzymes in broilers. Furthermore, the breast meat of the broilers displayed an increased protein content with a simultaneous reduction in the fat content after DJFP treatment (p < 0.05). Essential amino acid levels were higher in the DJFP-supplemented groups (p < 0.05). The sum of saturated fatty acids was lower, and that of monounsaturated fatty acids (MUFAs) and the polyunsaturated fatty acid/saturated fatty acid ratio (PUFA/SFA) were higher in the DJFP-supplemented groups (p < 0.05). Together, these results indicate that up to 100 g/kg of dietary DJFP supplementation can enhance the growth performance and antioxidant capacity, meat composition, and amino acid and fatty acid composition in broiler breast meat. In conclusion, dietary DJFP supplementation is a healthy alternative to the use of synthetic antioxidants in broiler production, especially in regions rich in jujube resources.

Effect of Hop β-Acids Extract Supplementation on the Volatile Compound Profile of Roasted Chicken Meat

The increased interest in greener sources of antioxidants has spurred the research on natural alternatives to enhance poultry production. This study aimed to investigate the effects of natural antioxidant extracts’ (hop β-acids extract) diet supplementation at different concentrations (0, 30, 60, and 120 mg kg−1) on the volatile compound profile of roasted chicken meat. A method based on headspace solid-phase micro-extraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was optimized by response surface design to extract the volatile compounds. The optimum extraction conditions were 80 °C and 45 min. A total of 95 volatile compounds were identified in roasted chicken meat, especially aldehydes, alkanes, alcohols, esters, and pyrazines. Principal component analysis (PCA) separated the samples as a function of β-acid supplementation, indicating that increased levels of supplementation lead to distinct volatile profiles in roasted chicken meat. Aldehydes such as octanal and hexanal (8.94% and 17.63%, respectively, for 30 mg kg−1 treatment) played an important role in distinguishing the samples. Those compounds are the main oxidation products of unsaturated fatty acids, which are possibly protected by the antioxidant properties of hop β-acid extracts. Some other compounds with odoriferous importance detected for this level of supplementation were: 2,6-dimethyl pyrazine (5.12%), 2-pentylfuran (2.94%), and 1-octen-3-ol (1.88%). This study significantly contributes to the elucidation of the impact of hops β-acids supplementation in the chicken meat aroma profile, opening new venues for its potential application.

Linking key husbandry factors to the intrinsic quality of broiler meat

Broiler farming is the fastest-growing animal production sector and broiler meat is the second most-consumed meat in the world. The intensification of broiler production often has a negative impact on the meat quality and carcass characteristics. Consumers, however, expect a quality product from animals reared extensively on farms providing good animal welfare, often intuitively associated with extensive farming practices. Therefore, this literature review investigates how the critical factors contributing to the degree of extensiveness of broiler production affect the quality of meat. We used the data from scientific articles published in the years 2012-2021 to analyze the effect of diet (n = 409), genetics (n = 86), enrichment (n = 25), and stocking density (n = 20) on meat quality and carcass characteristics. Minerals and microelements supplementation in the diet improved all the meat quality aspects: sensory, physical, and chemical in most studies. Minerals and enzymes in the diet had beneficial effects on carcass characteristics, unlike feed restriction and ingredient substitutions. The impact of outdoor access on meat quality and carcass characteristics was most frequently examined, in contrast to the use of perches or effects of litter quality. Overall, enrichment did not affect the meat's sensory or physical parameters, but outdoor access improved its lipid composition. Lower stocking density deteriorated intramuscular fat content, decreased tenderness and juiciness, yet lowered cooking and drip loss, and increased carcass and breast muscle yields. When it comes to genetics, in general, slow growing broiler strains have better meat quality parameters, especially regarding yellowness (b*), redness (a*), cooking and drip loss. Our review shows that the factors which contribute to extensiveness of broiler production systems and birds' welfare also affect meat quality and the carcass characteristics.

Spirulina as Animal Feed: Opportunities and Challenges

Increasing demand for protein, especially animal-based proteins and the large amounts of protein feed inputs required for production, has largely driven the research on spirulina as an animal feed. This short communication summarizes the results from two larger research projects investigating spirulina as an animal feed. Overall, spirulina appears to be a prospective protein source in poultry and pork production, as well as aquaculture. However, spirulina as a feed can have implications for system productivity and end product quality, depending on animal production system. Neither swine productivity nor product quality was negatively affected with spirulina as a feed, which is likely due to the low amounts of protein required in swine finishing diets. Spirulina as a feed does negatively affect poultry and fish productivity as well as alter product quality, primarily raw meat color. Therefore, future research focused on sustainability analysis and product processing and acceptance should investigate the trade-offs of incorporating spirulina into poultry and fish diets.

Algae as a Source of Natural Flavors in Innovative Foods

As a result of their nutritive values, algae have been used as a food resource for centuries, and there is a growing interest to use them as enrichment ingredients in food products. However, food product acceptance by consumers is strongly linked to their organoleptic properties, especially the aroma, taste, and a combination of the two, flavor. With regard to edible algae, "fresh seashore", "seafood-like", "cucumber green", and "earthy" are descriptors commonly used to define their aromas. Several families of molecules participate in the diversity and peculiarities of algal aromas: pungent sulfur compounds and marine halogenated components but also herbaceous fatty acid derivatives and fruity-floral terpenoids. In both macroalgae (seaweeds) and microalgae, these compounds are studied from a chemistry point of view (identification and quantification) and a sensorial point of view, involving sensorial evaluation by panelists. As a whole food, a food ingredient, or a feed, algae are valued for their nutritional composition and their health benefits. However, because the acceptance of food by consumers is so strongly linked to its sensorial features, studies have been performed to explore the aromas of algae, their impact on food, their evolution through processing, and their ability to produce selected aromas using biotechnology. This review aims at highlighting algal aromas from seaweed and microalgae as well as their use, their handling, and their processing in the food industry.